Antimicrobial composition

ABSTRACT

The present invention relates to an antimicrobial composition and a method for disinfection involving the antimicrobial composition. It particularly relates to an antimicrobial composition for personal cleaning, oral care or hard surface cleaning applications. It was found that compositions comprising one or more monosubstituted phenols, terpineol and a carrier provide synergistic antimicrobial action. In a preferred aspect the composition also comprises 1 to 80%-wt of one or more surfactants.

FIELD OF THE INVENTION

The present invention relates to an antimicrobial composition and amethod for disinfection involving the antimicrobial composition. Itparticularly relates to an antimicrobial composition for personalcleaning, oral care or hard surface cleaning applications.

BACKGROUND TO THE INVENTION

Sanitising and disinfecting soap or cleaning compositions are of greatbenefit to individuals, since proper use generally may reduce the numberof germs and pathogens the individual is exposed to. Thus, suchcompositions may for instance play an important role in reducing theoccurrence and spread of infectious diseases.

Sanitising and disinfecting soap compositions comprising chlorine-basedantimicrobial agent such as triclosan are known. Such compositionsrequire a rather long contact time to provide efficacious antimicrobialaction. In practice, users, in particular children, do not spend a longtime on cleansing and as a result cleaning with such compositions doesnot provide adequate prevention from surface or topical infection oradequate protection against diseases. The user, iN spite of cleaning hishands, is generally likely to end up with relatively inadequatebacterial removal from his skin. Therefore, he may cause contaminationof further animate and/or inanimate surfaces and contribute to thespreading of pathogens and consequent diseases. Users in general andchildren in particular who wash contaminated hands before meals withslow-acting antimicrobial compositions for relatively short time are atrisk of contracting diseases.

Similarly in the area of hard surface cleaning, e.g. cleaning of floors,table tops or utensils, the antimicrobial in the compositions are incontact with the substrate for less than a few minutes after which thesurface is either wiped off or rinsed with water. These short timescales of cleaning action are ineffective in providing the desiredbenefit since most known antimicrobials commonly used in such productstake many minutes to hours to provide the desired kill of microbes.

Therefore, there is a need of providing a composition that—uponapplication—provides relatively more efficacious antimicrobial actionduring a relatively short cleaning period, preferably about 30 secondsor less.

A well-established class of antimicrobially active compounds arephenolic compounds [P A Goddard and K A McCue in “Disinfection,Sterilisation and Preservation”, ed. S S Block, 5^(th) edition,Lippincott, Williams and Wilkins, Philadelphia, 2001 pp. 255-282].However, not every phenolic compound is suitable as an antimicrobialagent. Moreover, many phenols—even if they are antimicrobiallyactive—may exhibit undesirable side-effects, such as corrosiveness,malodour and irritating or sensitising effects when applied on the humanor animal skin. In addition, small changes to molecular structure may ingeneral strongly affect both the desired and the undesired effects in agenerally unpredictable way.

A particularly well-known group of phenolic compounds are halogenatedphenolics. However, there are concerns about the usage of chlorinatedphenols as antimicrobials and herbicides, since they are perceived aspollutants, and are often associated with environmental toxicity,bioaccumulation and low biodegradability [J P Voets et al, J. Appl.Bact. vol 40, p. 67-72 (1976); “Chlorophenols in the terrestrialenvironment” J Jensen, Reviews of environmental contamination andtoxicology, Vol 146 pp 25-51 (1996)).

WO 2010/046238 A1 describes an effective antimicrobial composition whichprovides rapid kill of pathogenic bacteria and which comprises 0.01 to5% by weight of thymol, 0.01 to 5% by weight of terpineol and a carrier.WO 2010/046238 A1 also discloses a method of disinfecting a surfaceincluding the step of applying the above composition to the surface.

EP 0 791 362 A2 discloses a composition comprising a peroxygen bleach,from 0.003% to 5% by weight of the total composition of a cyclic terpeneor a derivative thereof and from 0.003% to 5% by weight of the totalcomposition of a phenolic compound. The composition can be used todisinfect various surfaces, including animate and inanimate surfaces. Itwas found that the use of a cyclic terpene and/or a derivative thereof(e.g. eucalyptol) together with a phenolic compound (e.g. eugenol,carvacrol, ferulic acid) results in a synergistic effect on disinfectingperformance. Suitable cyclic terpenes include any mono- or polycycliccompound including at least one isoprenic unit, preferably 1 or 2, saidisoprenic unit may comprise one or more hetero atoms, preferably,oxygen, and said isoprenic unit may be substituted at any carbon by H, alinear or branched, saturated or unsaturated hydrocarbon chain, analkoxylated hydrocarbon chain, or an aryl chain having from 1 to 20carbon atoms, more preferably from 1 to 4. Highly preferred cyclicterpenes or derivatives thereof are limonene, menthol, eucalyptol,terpineol and mixtures thereof.

The phenolic compounds of the composition according to EP 0 791 362 A2have the following formula:

wherein R, R1, R2, R3, R4 independently are H, a linear or branched,saturated or unsaturated hydrocarbon chain having from 1 to 20 carbonatoms, an alkoxylated hydrocarbon chain according to the formula Ra(A)nwherein Ra is a linear or branched, saturated or unsaturated hydrocarbonchain having from 1 to 20 carbon atoms, wherein A is butoxy, propoxyand/or ethoxy, and n is an integer of 1 to 4, or an aryl chain havingfrom 1 to 20 carbon atoms. Eugenol, carvacrol and ferulic acid arepreferred phenolic compounds. EP 0 791 362 A2 also discloses a processof disinfecting an inanimate surface, in particular fabrics, with theabove composition. In different modes of fabric disinfecting, contactingtimes from 1 to 30 minutes, or from 1 minute to 24 hours are preferred.

U.S. Pat. No. 6,152,152 discloses a method for washing dishes, whichcomprises applying to an absorbent implement an undiluted liquiddishwashing composition comprising a) from 10% to 60% by weight of asurfactant, b) from 1% to 15% by weight of a hydrotrope selected fromthe group consisting of salts of cumene sulfonate, toluene sulfonate,xylene sulfonate, benzene sulfonate and mixtures thereof; and c) from0.1% to 3% by weight of the total composition of an unsaturatedaliphatic terpene alcohol or derivative, and d) a phenolic compound. Thephenolic compound is of the same formula as given for EP 0 791 362 A2above. The preferred aliphatic terpene alcohol is geraniol; preferredphenolic compounds are eugenol, thymol, and mixtures thereof. It wasfound that such dishwashing compositions can fulfil the purpose ofreducing or eliminating bacterial growth on absorbing dish implements.To achieve this, the dish implement is preferably contacted, e.g. soakedwith neat product and left to dry.

WO 04/035723 is directed to concentrated cleaning and/or disinfectingcompositions which bloom when diluted in water. It discloses a hardsurface cleaning concentrate composition comprising: a) from about 0.05to about 10 wt % of a non-cationic antimicrobial agent; b) from about 1to about 20 wt % of a water soluble organic solvent c) from about 1 toabout 20 wt % of an anionic soap surfactant; d) from about 1 to about 15wt % of a hydrocarbon diluent; e) from about 0.001 to about 20 wt % ofpine oil which is at least 60% terpene alcohols; f) optionally, fromabout 0 to about 10 wt % of optional materials selected from dyes,colorants, pH stabilizers and buffers, non-ionic surfactants,fragrance/fragrance enhancers, viscosity modifiers, insect repellants,and light stabilizers; and g) the balance being water. Phenol basednon-cationic antimicrobials are preferred. Important constituents of thepine oil include terpineol. It is shown that a composition comprising1.50 wt % of aromatic hydrocarbons (Aromatic 200), 1.00 wt % of Pine Oil80, 1.50 wt % of PCMX (p-chloro-m-xylenol), 2.00 wt % of isopropylalcohol, 20 wt % of NaCOS (sodium castor oil soap—40%), 0.40 wt % ofinsect repellant. 73.60 wt % water and added dye provides a Log 10reduction value of greater than 3 In a microbial reduction suspensiontest, after a contact time of 15 seconds, using 1:60 to 1:100 dilutionsof the composition in water and one part of organism suspension(Staphylococcus aureus or Salmonella choleraesuis).

FR 2 697 133 discloses biocidal and/or biostatic compositions,comprising mono-oxygenated sesquiterpenes of general formula C₁₅H_(x)O,wherein x is between 20 and 26 and aromatic compounds.

Despite the general availability of antimicrobial compounds andcompositions, there remains a continuous need to find alternativeantimicrobial compositions and active compounds that are suitable foruse in such compositions. In particular, alternative compositionsproviding fast antimicrobial action remain highly desirable in view ofcurrent consumer habits. Such alternatives may reduce the dependency oncurrent raw materials. Moreover, in the field of antimicrobials, theavailability of alternatives may reduce the risk of development ofmicrobial resistance or insensitivity to particular antimicrobialcompounds.

In addition, there is a continued need to reduce the total amount ofactive Ingredients required in such an antimicrobial composition. Thisneed may for instance be driven by the desire for cost-efficiency,because such compositions are particularly relevant to developingcountries. Moreover, reducing the amounts may also be beneficial forenvironmental reasons.

A particular problem of certain antimicrobial actives, and especiallysome phenolic compounds such as thymol is that they are generallywell-perceptible due to their olfactory properties. Although the lattermay—at least for some species—be appreciated in certain fragrancecompositions, they are considered too intense by some users when theyare applied at concentrations efficacious in rapid disinfection.Additionally, a lower concentration of odoriferous compounds or theavailability of antimicrobial compounds that are less or not odoriferousallows greater flexibility to the manufacturer in providing alternativescents to his composition at lower doses. Hence there is a need toprovide alternative antimicrobial compositions and methods thatpreferably require lower concentrations and/or have a more acceptablesensory profile.

In view of the above-observed problems and drawbacks of the prior art,it is an object of the present invention to provide alternativeantimicrobial compositions, in particular antimicrobial compositionsthat do not depend on halogenated phenols for their antimicrobialefficacy.

It is a particular object of the invention to provide such compositions,requiring a lower dose of antimicrobial compounds.

Similarly, it is an object of the present invention to provide anantimicrobial composition in which the olfactory contribution of theantimicrobially active compounds is reduced or in which the activecompound contributes to providing a consumer-acceptable or evenconsumer-appreciated scent.

It is another particular object of the invention to provide anantimicrobial composition that contributes to reducing the requiredcontact time in a method for disinfection of a surface.

In particular, it is an object of the invention to provide anantimicrobial composition which gives improved disinfection duringcleansing of surfaces of the human body, such as the skin and the oralcavity.

It is yet another object of the present invention to provide analternative method for sanitising and/or disinfecting, in particular ofsurfaces.

It is a further object of the invention to provide a method fordisinfection with a reduced disinfection time. More specifically, it isan object of the invention to provide a method, wherein the disinfectiontime of the method is less than 300 seconds, preferably less than 60seconds, and more preferably less than 15 seconds.

In particular, it is an object of the invention to provide a method fordisinfection that gives improved disinfection during cleansing ofsurfaces, in particular hard surfaces, or surfaces of the human body,such as the skin and the oral cavity.

SUMMARY OF THE INVENTION

We have now found that one or more of the above objects are met by thepresent invention. Thus, we have found that compositions comprisingselected monosubstituted phenols and terpineol provide synergisticantimicrobial action. Such compositions provide similar or moreefficacious anti-microbial action, at similar or lower concentrationswhen compared to thymol and alpha-terpineol. In particular, we foundthat combinations of monosubstituted phenols and terpineol according tothis invention are capable of very fast antimicrobial action. Forinstance, we found that complete microbial inactivation could beeffected with compositions according to the present invention after acontact time of only 15 seconds. Moreover, the compositions according tothe present invention do not rely on the presence of halogenated phenolsfor their antimicrobial efficacy.

Accordingly, in a first aspect the invention provides an antimicrobialcomposition comprising:

-   -   i. 0.001 to 5% by weight of one or more monosubstituted phenols,    -   ii. 0.001 to 5% by weight of terpineol, and    -   iii. a carrier    -   wherein the one or more monosubstituted phenols have the        following structure

-   -   wherein        -   the substituent R₁ is selected from the group consisting of            -   linear C₃ to C₅ alkyl,            -   isopropyl            -   branched C₄ alkyl,            -   linear C₃ to C₃ alkenyl,            -   linear C₄ or C₅ alkadienyl,            -   branched C₄ alkenyl,            -   cyclopentyl,            -   cyclopentenyl,            -   cyclohexyl,            -   cyclohexenyl,            -   phenyl, and            -   benzyl;    -   and wherein        -   the terpineol is selected from the group consisting of            alpha-terpineol, beta-terpineol, gamma-terpineol,            delta-terpineol, 4-terpineol, and mixtures thereof.

According to a second aspect of the invention, there is provided amethod of disinfecting a surface comprising the steps of

-   -   a. applying a composition according to the invention on to the        surface; and    -   b. removing the composition from the surface.

In a third aspect, the invention provides the use of a compositionaccording to the invention for improved hygiene.

DETAILED DESCRIPTION OF THE INVENTION

For the avoidance of doubt, any feature of one aspect of the presentinvention may be utilised in any other aspect of the invention. The word“comprising” is intended to mean “including” but not necessarily“consisting of” or “composed of.” Thus, the term “comprising” is meantnot to be limiting to any subsequently stated elements but rather tooptionally also encompass non-specified elements of major or minorfunctional importance. In other words, the listed steps or options neednot be exhaustive. Whenever the words “including” or “having” are used,these terms are meant to be equivalent to “comprising” as defined above.It is noted that the examples given in the description below areintended to clarify the invention and are not intended to limit theinvention to those examples per se.

Except in the examples, or where otherwise explicitly indicated, allnumbers in this description indicating amounts of material or conditionsof reaction, physical properties of materials and/or use are to beunderstood as modified by the word “about”. Unless specified otherwise,numerical ranges expressed in the format “from x to y” are understood toinclude x and y. When for a specific feature multiple preferred rangesare described in the format “from x to y”, it is understood that allranges combining the different endpoints are also contemplated.

Phenol in its strict sense refers to hydroxybenzene (C₆H₅OH), but whereappropriate the word phenol may in its wider meaning as understood bythe skilled person also refer to a member of the class of compoundswhich comprise at least one such a characteristic hydroxybenzene moiety.

Throughout this description, the term disinfection refers to reductionof the number of viable microorganisms in a given medium or on a givensurface by physical or chemical means. Typically, disinfection involvesthe destruction or inactivation of said microorganisms. Both animate andinanimate media and surfaces are contemplated.

The term “microbicide” refers to a compound capable of killing,inhibiting the growth of or controlling the growth of microorganisms ata locus; microbicides include bactericides, fungicides and algaecides.The term “microorganism” includes, for example, fungi (such as yeast andmould), bacteria and algae.

The antimicrobial composition comprises one or more monosubstitutedphenols, terpineol and a carrier. Various components of theantimicrobial composition are described below.

The compositions of the present Invention are preferred fornon-therapeutic use, and more particularly preferred for use in cleaningsurfaces of human body including skin, hair or oral cavity or for hardsurface cleaning applications.

Monosubstituted Phenols

The antimicrobial composition according to the invention comprises 0.001to 5% by weight of one or more monosubstituted phenols. The compositioncomprises preferably 0.005 to 4.5 wt-%, more preferably 0.01 to 4 wt-%,even more preferably 0.02 to 3 wt-%, yet more preferably 0.03 to 2 wt-%,still more preferably 0.04 to 1 wt-%, even more preferably 0.05 to 0.75wt-% and still more preferably 0.1 to 0.5 wt-% of the one or moremonosubstituted phenols. In compositions intended to be diluted beforeapplication, the minimum preferred concentrations of the one or moremonosubstituted phenols can be higher. For example, when washing handswith water and a composition according to the invention, the latherproduced, typically is a 50 wt % dilution of the original composition.Similarly, in body wash situations, soap bars or soap liquids aretypically diluted until about 8 wt % soap in water, corresponding to anapproximately tenfold dilution of the product. Therefore, compositionsaccording to the invention intended for dilution upon use preferablycomprise 0.05 to 4.5 wt-%, more preferably 0.1 to 4 wt-%, even morepreferably 0.2 to 3 wt-%, still more preferably 0.4 to 1 wt-%, and stillmore preferably 0.5 to 1 wt-% of the one or more monosubstitutedphenols. Thus, the concentration of the one or more monosubstitutedphenols in the antimicrobial composition is preferably such that, whenthe composition is diluted or dissolved with a suitable medium duringuse, the concentration in the diluted or dissolved mixture is stillsufficient to be antimicrobially efficacious.

The monosubstituted phenol may be a single compound or may be a mixtureof the monosubstituted phenols as detailed below. In certain preferredembodiments, mixtures of monosubstituted phenols are preferred, sincesuch mixtures may show increased antimicrobial activity against a widerrange of microbes. On the other hand, for reasons including e.g. controlover the formulation, it is preferred that in case the compositionaccording to the invention comprises a mixture of such monosubstitutedphenols, the mixture preferably comprises at least 30%, more preferablyat least 50%, even more preferably at least 70% and still morepreferably at least 90% by weight of one monosubstituted phenol withrespect to the total weight of the monosubstituted phenols.

At concentration ranges of the monosubstituted phenols below the lowerconcentration limits of the monosubstituted phenols, the desired fastacting antimicrobial kinetics in combination with terpineol would not bemet. At concentrations higher than the higher preferred concentrationsof monosubstituted phenols, when in combination with a terpineol, whilethe kinetics of action would not be compromised, the present inventorshave found that unlike in therapeutic/pesticidal/herbicidal applicationswhere sensorial aspects are not critical, in the present application,which is preferably a personal cleaning, oral care or hard surfacecleaning applications, the product is in contact with hands, mouth orother body parts, the sensorial aspects including smell and skin feelwould be compromised.

The one or more monosubstituted phenols have the following structure

wherein the substituent R₁ is selected from the group consisting oflinear C₃ to C₅ alkyl, isopropyl, branched C₄ alkyl, linear C₃ to C₅alkenyl, linear C₄ or C₅ alkadienyl, branched C₄ alkenyl, cyclopentyl,cyclopentenyl, cyclohexyl, cyclohexenyl, phenyl, and benzyl.

All positional isomers of the monosubstituted phenols are contemplated.The R₁ group can be substituted to any of the carbons of the phenolring. Thus, with R₁ is linear C₅ alkyl, for example, the one or moremonosubstituted phenols can be selected from 2-pentyl phenol, 3-pentylphenol, and 4-pentyl phenol.

The substituent R₁ is preferably selected from the group consisting oflinear C₃ to C₅ alkyl, branched C₄ alkyl, linear C₃ to C₅ alkenyl,linear C₄ or C₅ alkadienyl, branched C₄ alkenyl, cyclopentyl,cyclopentenyl, cyclohexyl, cyclohexenyl, phenyl, and benzyl.

More preferably, the substituent R₁ is a branched C₄ alkyl or a branchedC₄ alkenyl group, and even more preferably, the substituent R₁ isselected from the group consisting of tert-butyl, sec-butyl, andisobutyl.

Alternatively, in some embodiments, the substituent R₁ preferably isselected from the group consisting of cyclopentyl and cyclohexyl. Morepreferably, R₁ is cyclopentyl. Still more preferably, themonosubstituted phenol is 2-cyclopentylphenol. This preference, which isfor instance relevant to embodiments directed to treatment of the skin,is based on the favourable toxicological profile of these compounds.

Alternatively, it is particularly preferred that the one or moremonosubstituted phenols are selected from the group consisting of4-propylphenol, 4-n-butylphenol, 4-pentylphenol, 2-tert-butylphenol,3-tert-butylphenol, 2-sec-butylphenol, 4-sec-butylphenol,2-cyclopentylphenol, 4-cyclopentylphenol, 2-cyclohexylphenol,2-(prop-1-enyl)phenol, (more preferably (E)-2-(prop-1-enyl)phenol,2-allylphenol, 3-phenylphenol, 2-benzylphenol, and 4-benzylphenol.

Alternatively, it is similarly preferred that the one or moremonosubstituted phenols are selected from the group consisting of2-n-propyl phenol, 3-n-propyl phenol and 4-n-propyl phenol.

It is even more preferred that the one or more monosubstituted phenolsare selected from the group consisting of 2-tert-butylphenol,3-tert-butylphenol, 2-sec-butylphenol, 4-sec-butylphenol,2-cyclopentylphenol, 4-cyclopentylphenol, and 2-cyclohexylphenol.

It is still more preferred that the one or more monosubstituted phenolsare selected from the group consisting of 2-tert-butylphenol,3-tert-butylphenol, 2-sec-butylphenol, and 4-sec-butylphenol.

In case the one or more monosubstituted phenols are phenylphenols, it ispreferred that they are selected from 2-phenyl phenol and 3-phenylphenol.

In another preferred embodiment, the one or more monosubstituted phenolsare preferably selected from the group consisting of 2-n-propylphenol,4-n-butylphenol, 4-sec-butylphenol, 2-cyclopentylphenol, and4-cyclopentyl phenol.

In case the carrier or the dissolution medium during later applicationis water-based, it can be advantageous if the one or moremonosubstituted phenols are sufficiently water-soluble. Themonosubstituted phenols are sufficiently water-soluble if they aresoluble to at least the minimum concentration required in theantimicrobial composition according to the invention.

The unsaturated R₁-substituents according to the invention, for examplethe alkenyl, alkadienyl, and cycloalkenyl substituents, comprise a C—Cdouble bond, which may take any position in the substituent. Thus, thecyclopentenyl substituents, for instance include (cyclopent-1-en-1-yl)-,(cyclopent-2-en-1-yl), and (cyclopent-3-en-1-yl)-substituents.

Several non-limiting examples of the structures of the one or moremonosubstituted phenols according to the present invention are providedin Table 1.

TABLE 1

Advantageously, some compounds according to the invention have a weakerodour, when compared to that of thymol, or an odour which can be moreappreciable to the consumer, when dosed into the compositions accordingto the invention at efficacious levels. This benefit especially appliesto for instance 2-(prop-1-enyl)phenol, 4-propylphenol, 4-n-butylphenol,4-pentylphenol, 4-benzylphenol, 2-cyclopentylphenol, and4-cyclopentylphenol. Therefore, these are preferred compounds.

Mixtures of preferred monosubstituted phenols are also preferred. Whereapplicable, the different stereoisomers of the monosubstituted phenolsare contemplated. Thus, compositions comprising enantiomerically purecompounds, racemic mixtures and other mixtures of differentstereoisomers of the monosubstituted phenols are equally preferable,unless indicated otherwise in this application.

Without wishing to be bound by theory, it is believed that thesynergistic mode of antimicrobial action of the monosubstituted phenolsaccording to the present invention in combination with terpineol issimilar for the different respective monosubstituted phenols.

The extent to which the monosubstituted phenols according to the presentinvention are soluble in water or in organic solvents may be suitablyexpressed by the logarithm of the octanol/water partitioningcoefficient, log {P}. This partition coefficient s a measure for thedistribution of a solute between water and octanol at equilibrium. Thevalue of the partitioning coefficient may also be predicted usingcomputational methods. A commonly used predicted value is the so-calledAlogP value. A definition and preferred method of calculation of AlogPvalues is provided in A. K. Ghose, V. N. Viswanadhan, and J. J.Wendoloski, J. Phys. Chem. A, vol 102, pag. 3762 (1998). Due to thestandardised calculation as described by Ghose et al, AlogP values ofdifferent compounds can be compared with one another and used to assessthe similarity of or difference between different compounds. Forinstance, phenol has an AlogP value of 1.59 and thymol has an AlogPvalue of 3.27. Such comparison can also extend to other properties thatare believed to be related to the same molecular properties thatunderlie the value of AlogP. Though not wishing to be bound by theory inthis respect, it is believed that there is some correlation betweenAlogP and the antimicrobial efficacy of the monosubstituted phenolsaccording to the present invention. Therefore, the monosubstitutedphenols according to the present invention preferably have an AlogPvalue of between 2.0 and 4.5, more preferably between 2.2 and 4.4, evenmore preferably between 2.4 and 4.1 and still more preferably between2.5 and 4.0.

Suitable monosubstituted phenols according to the present invention maybe commercially sourced or obtained via synthetic chemical methods. Suchmethods are generally well-known to the person skilled in the art. Forexample, alkyl substituted phenols may be synthesised by Friedel Craftsreaction of phenol with an olefin in the presence of an acid catalystsuch as sulphuric acid, acid activated silicas, boron trifluoride oraluminium chloride. Arylation of phenol with benzene can be achievedunder similar reaction conditions, sometime termed the Scholl reaction[J March, “Advanced Organic Chemistry: Reactions, Mechanisms andStructure”, 4^(th) edition John Wiley, New York, 1992, pages 534-539; H.Fiege, H-W. Voges, T. Hamamoto, S. Umemura. T. Iwata, H. Miki, Y.Fujita, H-J. Buysch., D. Garbe and W. Paulus, “Phenol Derivatives” inUllmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Volume 26,page 526, 2000]

Terpineol

The antimicrobial composition according to the invention comprises 0.001to 5% by weight of terpineol. The composition comprises preferably 0.005to 4.5 wt-%, more preferably 0.01 to 4 wt-%, even more preferably 0.02to 3 wt-%, yet more preferably 0.03 to 2 wt-%, still more preferably0.04 to 1 wt-%, still more preferably 0.05 to 0.75 wt-% and even morepreferably 0.1 to 0.5 wt-% of terpineol. In compositions intended to bediluted before application, the minimum preferred concentrations of theterpineol can be higher, for the same reasons as for the monosubstitutedphenols. Therefore, compositions according to the invention intended fordilution upon use preferably comprise 0.05 to 4.5 wt-%, more preferably0.1 to 4 wt-%, even more preferably 0.2 to 3 wt-%, still more preferably0.4 to 1 wt-%, and still more preferably 0.5 to 1 wt-% of the terpineol.Any of these concentration ranges for the terpineol is preferablycombined with any of the concentration ranges for the one or moremonosubstituted phenols specified above. Therefore, the antimicrobialcomposition according to the invention for example comprises:

-   -   a. 0.01 to 0.4% by weight of the one or more monosubstituted        phenols: and    -   b. 0.05 to 1% by weight of the terpineol.

The terpineol may be a single compound or may be a mixture of theterpineol isomers as detailed below. Mixtures of terpineols arepreferred, since such mixtures may show increased antimicrobial activityagainst a wider range of microbes. In case the composition according tothe invention comprises such a mixture of terpineols, the mixturepreferably comprises at least 30%, more preferably at least 50%, evenmore preferably at least 70% and still more preferably at least 90% byweight of one terpineol isomer with respect to the total weight of theterpineol. Preferably, said one terpineol isomer is alpha-terpineol. Thepreferred concentrations ranges of the terpineol are important for thesame reasons as the preferred concentration ranges of the one or moremonosubstituted phenols in meeting the desired fast acting antimicrobialkinetics while not being sensorially unpleasant when used in productsfor personal cleaning, oral care or hard surface cleaning applications.

Terpineol Isomers

Terpineol exists as different isomers, which all are consideredterpineols. The terpineol is selected from the group consisting ofalpha-terpineol, beta-terpineol, gamma-terpineol, delta-terpineol,4-terpineol, and mixtures thereof. More preferably, the terpineol isselected from the group consisting of alpha-terpineol, beta-terpineol,gamma-terpineol, delta-terpineol, and mixtures thereof. In nature, theisomeric compounds alpha-terpineol, beta-terpineol and gamma-terpineolare among the most abundant terpineols and often occur together inmixtures. Therefore even more preferably, the terpineol is selected fromthe group consisting of alpha-terpineol, beta-terpineol,gamma-terpineol, and mixtures thereof. The structures of these isomersare schematically depicted in Table 2 below.

TABLE 2 Terpineol isomers

Where applicable, the different stereoisomers of these terpineol isomersare contemplated. For instance, cis-beta-terpineol andtrans-beta-terpineol are both contemplated. Thus, compositionscomprising enantiomerically pure radicals, racemic mixtures and othermixtures of different stereoisomers are equally preferable.

These terpineols are all members of the menthenol class of compounds [AL Gunatilaka, Natural products in Plants: Chemical Diversity in theWiley Encyclopedia of Chemical Biology, pp 1-17 and E Breitmaier,Terpenes: flavors, fragrances, pharmaca, pheromones; p. 17, Wiley-VCH,2006], also termed oxytetrahydrocymenes [F Heusler, The Chemistry of theTerpenes, trans. F J Pond, P Blakistons's son & Co, Philadelphia, 1902,p. 21] which may be defined as monohydroxy alcohol derivatives ofp-menthene, with the generic formula C₁₀H₁₇OH. Combinations of theseterpineol isomers are often found together in nature, because it isgenerally believed that their biosyntheses proceed via closely relatedsynthetic pathways. Without wishing to be bound by theory, it isbelieved that the mode of antimicrobial action of these terpineolisomers in combination with the monosubstituted phenols according to thepresent invention is similar.

The terpineols may also be referred to by the alternative names asdetailed below in Table 3.

TABLE 3 alpha-terpineol ρ-menth-1-en-8-ol 2-(4-methylcyclohex-3-en-1-yl)propan-2-ol beta-terpineol ρ-menth-8-en-1-ol1-methyl-4-(prop-1-en-2-yl)- cyclohexanol gamma-terpineolρ-menth-4(8)-en-1-ol 1-methyl-4-(propan-2- ylidene)-cyclohexanoldelta-terpineol ρ-menth-1(7)-en-8-ol 2-(4-methylenecyclo-hexyl)propan-2-ol 4-terpineol ρ-menth-1-en-4-ol 1-isopropyl-4-methylcyclohex-3-enol

Terpineol may be added to the antimicrobial composition in purifiedform. Alternatively pine oil comprising terpineol may be added to theantimicrobial composition while ensuring that terpineol is present inthe desired concentration in the composition of the present invention.

Carrier

The antimicrobial composition according to the invention comprises acarrier. The carrier is preferably selected from the group consisting ofwater, oil, solvent, inorganic particulate material, starch, air andmixtures thereof. The carrier is preferably from 0.1 to 99% by weight ofthe composition. The antimicrobial composition may be in form of asolid, liquid, gel, paste or soft solid and the carrier may be selectedby a person skilled in the art depending on the format of theantimicrobial composition.

Examples of inorganic particulate materials include clay, talc, calcite,dolomite, silica, and aluminosilicate. Examples of oils include mineraloils, oils of biological origin (e.g. vegetable oils), andpetroleum-derived oils and waxes. The oils of biological origin arepreferably triglyceride-based. Preferably, the carrier oil is not aperfume oil. Thus, the carrier oil preferably does not substantiallycontribute to the odour of the composition, more preferably it does notcontribute to that odour. Examples of solvents include alcohols, ethersand acetone. The starch may be natural starch obtained from food grainsor may be a modified starch.

In certain preferred embodiments, suitable solvents include, forexample, water; glycols, including ethylene glycol, propylene glycol,diethylene glycol, dipropylene glycol, polyethylene glycol, andpolypropylene glycol; glycol ethers; alcohols, such as methanol,ethanol, propanol, phenethyl alcohol and phenoxypropanol; ketones,including acetone and methyl ethyl ketone; esters, including ethylacetate, butyl acetate, triacetyl citrate, and glycerol triacetate;carbonates, including propylene carbonate and dimethyl carbonate; andmixtures thereof. It is preferred that the solvent is selected fromwater, glycols, glycol ethers, esters and mixtures thereof. In certainpreferred embodiments, suitable solid carriers include, for example,cyclodextrin, silicas, diatomaceous earth, waxes, cellulosic materials,alkali and alkaline earth (e.g., sodium, magnesium, potassium) metalsalts (e.g., chloride, nitrate, bromide, sulfate) and charcoal.

Air can for instance be used as a carrier when the monosubstitutedphenols according to the invention and/or the terpineol are atomised orotherwise dispersed as a fine mist.

Particularly preferred carriers are water or oil/solvent and even morepreferred is a carrier that is a mixture of water and oil. Thus, in manyof the envisaged applications like personal care/washing, oral care andhard surface cleaning, the antimicrobial composition may be formulatedwith either an aqueous base or an oil/solvent base. Compositions with anaqueous base (water being the carrier), can also for instance beproducts in gel format. Compositions with an oil/solvent base can forinstance be products in anhydrous stick form or propellant-containingproducts.

Thus, the antimicrobial composition can for instance, preferably be anantimicrobial anhydrous stick personal care composition on anoil/solvent base wherein the composition has a water content of lessthan 0.01% by weight, and wherein the composition preferably is free ofwater. Alternatively, the antimicrobial composition can for instance,preferably be an antimicrobial propellant-drivable personal carecomposition, also comprising a propellant. Air can also be used aspropellant, for instance in the form of compressed or liquefied air.

However, the most preferred product format has an emulsion base (waterand/or oil being the carrier) or is capable of forming an emulsion upondilution, e.g. soap products in liquid, solid, lotion or semisolid formfor hand wash, face wash, body wash, or shaving applications;toothpaste/dentifrices for oral care applications or products for hardsurface cleaning in bars or liquids form. If the product comprises anemulsion base, it preferably also comprises one or more surfactants asdescribed below.

Surfactants

The antimicrobial composition according to the invention preferablycomprises from 1 to 80% by weight of one or more surfactants.Surfactants may for instance advantageously contribute to the cleaningefficacy or the formulation stability of a composition.

Thus, the antimicrobial composition according to the inventionpreferably comprises

-   -   a. 0.001 to 5% by weight of the one or more monosubstituted        phenols according to the invention,    -   b. 0.001 to 5% by weight of terpineol    -   c. a carrier, and        from 1 to 80% by weight of one or more surfactants.

It is particularly preferred that the antimicrobial compositioncomprises from 1 to 80% by weight of one or more surfactants incombination with the one or more monosubstituted phenols, and theterpineol at their more preferred concentrations as specified above.

In general, the surfactants may be chosen from the surfactants describedin well-known textbooks like “Surface Active Agents” Vol. 1, by Schwartz& Perry, Interscience 1949, Vol. 2 by Schwartz. Perry & Berch,Interscience 1958, and/or the current edition of “McCutcheon'sEmulsifiers and Detergents” published by Manufacturing ConfectionersCompany or in “Tenside-Taschenbuch”, H. Stache, 2nd Edn., Carl HauserVerlag, 1981; “Handbook of Industrial Surfactants” (4th Edn.) by MichaelAsh and Irene Ash; Synapse Information Resources, 2008. Any type ofsurfactant, i.e. anionic, cationic, nonionic, zwitterionic or amphotericcan be used. Preferably, the one or more surfactants are anionic,nonionic, or a combination of anionic and nonionic surfactants. Morepreferably, the one or more surfactants are anionic.

A particularly preferred surfactant is soap. Soap is a suitablesurfactant for personal washing applications of the antimicrobialcomposition of the invention. The soap is preferably C₈-C₂₄ soap, morepreferably a C₁₀-C₂₀ soap and most preferably C₁₂-C₁₆ soap. The soap mayor may not have one or more carbon-carbon double bonds or triple bonds.The cation of the soap can for instance be an alkali metal, alkalineearth metal or ammonium. Preferably, the cation of the soap is selectedfrom sodium, potassium or ammonium. More preferably the cation of thesoap is sodium or potassium.

The soap may be obtained by saponifying a fat and/or a fatty acid. Thefats or oils may be fats or oils generally used in soap manufacture,such as tallow, tallow stearines, palm oil, palm stearines, soya beanoil, fish oil, castor oil, rice bran oil, sunflower oil, coconut oil,babassu oil, palm kernel oil, and others. In the above process the fattyacids are derived from oils/fats selected from coconut, rice bran,groundnut, tallow, palm, palm kernel, cotton seed, soyabean, castor etc.The fatty acid soaps can also be synthetically prepared (e.g. by theoxidation of petroleum or by the hydrogenation of carbon monoxide by theFischer-Tropsch process). Resin acids, such as those present in talloil, may be used. Naphthenic acids are also suitable.

Tallow fatty acids can be derived from various animal sources. Othersimilar mixtures, such as those from palm oil and those derived fromvarious animal tallow and lard are also included.

A typical fatty acid blend consists of 5 to 30%-wt coconut fatty acidsand 70 to 95%-wt fatty acids ex hardened rice bran oil. Fatty acidsderived from other suitable oils/fats such as groundnut, soybean,tallow, palm, palm kernel, etc. may also be used in other desiredproportions. The soap, when present in solid forms of the presentinvention, is preferably present in an amount of 30 to 80%, morepreferably from 50 to 80%, and even more preferably 55 to 75% by weightof the composition. The soap, when present in liquid forms of thecomposition is preferably present in 0.5 to 20%, more preferably from 1to 10% by weight of the composition.

Other preferred surfactants fatty acid glycinates and fattyamphocarboxylates. These surfactants are particularly preferred in skinand hair cleaning compositions, because of their mild detergency andhighly foaming nature. The fatty acid glycinates are salts of fatty acidamides of glycine, including for example sodium cocoyl glycinate. Thefatty amphocarboxylates are amphoteric surfactants including for examplesodium lauroamphoacetate (i.e. sodium2-[1-(2-hydroxyethyl)-2-undecyl-4,5-dihydroimidazol-1-ium-1-yl]acetate).Yet another example of suitable surfactants are derivatives ofisethionates, including acylisethionates.

The antimicrobial composition of the invention is also useful in hardsurface cleaning applications. In such applications, preferredsurfactants are nonionic surfactants, such as C₈-C₂₂, preferably C₈-C₁₆fatty alcohol ethoxylates, comprising between 1 and 8 ethylene oxidegroups when the product is in the liquid form. When the product for hardsurface cleaning applications is in the solid form, surfactants arepreferably selected from primary alkyl sulphates, secondary alkylsulphonates, alkyl benzene sulphonates, ethoxylated alkyl sulphates, oralcohol ethoxylate nonionic surfactants. The composition may furthercomprise an anionic surfactant, such as alkyl ether sulphate preferablythose having between 1 and 3 ethylene oxide groups, either from naturalor synthetic source and/or sulphonic acid. Especially preferred aresodium lauryl ether sulphates. Alkyl polyglucoside may also be presentin the composition, preferably those having a carbon chain lengthbetween C6 and C16. Other classes of useful surfactants include cationicsurfactants, such as long chain quaternary ammonium compounds andamphoteric surfactants such as betaines and alkyl dimethyl amine oxides.Suitable surfactant concentrations in liquid forms of hard surfacecleaning application are generally from about from 0.5 to 10%,preferably from 1 to 5% by weight of the composition. In solidcompositions, surfactant is preferably present in 5 to 40%, preferablyfrom 10 to 30% by weight of the composition.

The antimicrobial composition of the invention is useful in oral carecompositions e.g. in a dentifrice/toothpaste or an oral rinse product.In such applications, preferred surfactants are anionic, nonionic oramphoteric in nature, preferably anionic or amphoteric. The anionicsurfactant is preferably an alkali metal alkyl sulphate, more preferablya sodium lauryl sulphate (SLS). Mixtures of anionic surfactants may alsobe employed. The amphoteric surfactant is preferably a betaine, morepreferably an alkylamidopropyl betaine (wherein the alkyl group is alinear C₁₀-C₁₈ chain), and most preferably is cocoamidopropyl betaine(CAPB). Mixtures of amphoteric surfactants may also be employed.Suitable surfactant concentrations in oral care application aregenerally from about 2% to about 15%, preferably from about 2.2% toabout 10%, more preferably from about 2.5 to about 5% by weight of thetotal composition.

Thus, it is highly preferred that the antimicrobial compositions includesoap, alkyl sulphate or linear alkyl benzene sulphonate as thesurfactants. More preferably, the one or more surfactants are selectedfrom the group consisting of soaps, alkyl sulphates and linear alkylbenzene sulphonates.

Liquid and Solid Compositions

The antimicrobial composition may be in form of a solid, a liquid, a gelor a paste. A person skilled in the art can prepare compositions invarious formats by choosing one or more carrier materials and/orsurfactant. The antimicrobial compositions of the present invention areuseful for cleansing and care, in particular for skin cleansing and skincare. It is envisaged that the antimicrobial composition can be used asa leave-on product or a wash-off product, preferably a wash-off product.The antimicrobial composition of the present invention can also be usedfor cleansing and care of hard surfaces such as glass, metal, plasticand the like.

A particularly preferred carrier is water. When water is present, it ispreferably present in at least 1%, more preferably at least 2%, furthermore preferably at least 5% by weight of the composition. When water isthe carrier, both liquid and solid compositions are possible. Differentamounts of water may be preferred depending on the product format. Whenwater is the carrier, a preferred liquid antimicrobial compositionaccording to the invention comprises:

-   -   a. 0.01 to 5% by weight of the one or more monosubstituted        phenols,    -   b. 0.05 to 5% by weight of the terpineol    -   c. 10 to 99.9% by weight of water, and;    -   d. 1 to 30% by weight of surfactant.

The liquid antimicrobial composition is useful for skin cleansing, inparticular for hand wash or a face wash.

When water is the carrier, a preferred solid antimicrobial compositionaccording to the invention comprises:

-   -   a. 0.05 to 5% by weight of the one or more monosubstituted        phenols.    -   b. 0.05 to 5% by weight of the terpineol,    -   c. 5 to 30% by weight of water, and;    -   d. 30 to 80% by weight of surfactant.

The solid antimicrobial composition is preferably in form of a shapedsolid, more preferably a bar. The solid antimicrobial composition isparticularly useful for skin cleansing in particular for hand wash or aface wash.

Such a bar-shaped solid antimicrobial composition may for instance be asoap bar. Soap bar compositions are well-known and may be similar to thefollowing non-limiting example composition, comprising 75.6 wt-% ofanhydrous sodium soap, 1.0 wt-% of glycerine, 0.5 wt-% of sodiumcarbonate, 0.2 wt-% of EHDP (ethane-1-hydroxy-1,1-disphosphonate) acid,0.04 wt-% of EDTA (ethylenediaminetetraacetic acid) tetrasodium salt,8.5 wt-% of hydrated magnesium silicate (Talc), 0.7 wt-% of sodiumchloride, 0.05 wt-% of dyes, 0.75 wt-% perfume, 0.05 to 10 wt-% ofantimicrobial agents Including the monosubstituted phenols and theterpineol according to the present invention, and water up to 100 wt-%.

Alternatively, inorganic particulate material is also a suitablecarrier. When inorganic particulate material is the carrier, theantimicrobial composition is in a solid form. Preferably the inorganicparticulate material is talc. When the inorganic particulate material istalc, the solid antimicrobial composition is particularly useful as atalcum powder for application on face or body.

According to another alternative, a solvent different from water is apreferred carrier. Although any solvent can be used, alcohol is apreferred solvent. Short chain alcohols—in particular ethanol, propanol,and isopropanol—are particularly preferred as carrier for anantimicrobial wipe or an antimicrobial hand sanitiser composition.

Solvents like ethanol and isopropanol generally show antimicrobialefficacy themselves. However, they are also volatile and may readilyevaporate during application of the composition. Thus, their levels onthe surface that is treated might even reduce until below the minimumlevel required for antimicrobial action, before the minimum periodneeded for disinfection has passed. In contrast, the terpineol and themonosubstituted phenols according to the present invention are much lessvolatile and may therefore yield prolonged antimicrobial action afterapplying them to the skin.

Additional Ingredients

The composition may further comprise various additional ingredientsknown to a person skilled in the art. Such additional ingredientsinclude but are not limited to: perfumes, pigments, preservative,emollients, sunscreens, emulsifiers, gelling agents, thickening agents,humectants (e.g. glycerine, sorbitol), sequestrants (e.g. EDTA) orpolymers (e.g. cellulose derivatives for structuring such as methylcellulose)

Both terpineol and some of the monosubstituted phenols according to theinvention may contribute to the olfactory properties of the composition.Although some of these compounds might be applied for instance inperfume compositions, the present invention is directed towardsantimicrobial compositions. Therefore, the composition is preferably nota perfume composition, although other perfume components can be present.Here, a perfume composition is defined as a composition comprising aplurality of olfactory components, wherein the composition is solelyintended to provide a harmonious scent.

Synergistic Effect of the Invention

The inventors have surprisingly found that while one or more of themonosubstituted phenols according to the present invention alone orterpineol alone do not individually provide the fast antimicrobialkinetic action, a combination of one or more monosubstituted phenols andterpineol at the selective concentrations provides a synergisticantimicrobial action which is especially important in a wash offprocesses where the contact time of the antimicrobial actives with thesurface is low, i.e. of the order of less than 5 minutes, preferablyless than 2 minutes, further more preferably less than a minute and inmany cases less than 15 seconds.

Synergistic Combinations of Monosubstituted Phenols and Terpineol

The antimicrobial action of two or more active compounds is consideredadditive if the combined action merely results from the addition of theeffects the individual components would have in isolation. In contrast,the antimicrobial action of two or more active compounds is consideredto be synergistic if the combined effect of the two or more compounds isstronger than expected based on the assumption of additivity. Withoutwishing to be bound by theory, it is believed that the antimicrobialaction of the one compound is enhanced by the action of the othercompound and vice versa. Such enhancement may for Instance originatefrom cooperative interplay between the mechanisms of antimicrobialaction at the molecular level. Such enhanced antimicrobial action canmanifest itself for instance by the fact that lower concentrations ofactive compounds are required to obtain complete microbial kill, oralternatively, that the same extent of microbial kill is arrived at in ashorter time.

Whether an antimicrobial composition comprising two or more activecompounds is capable of synergistic antimicrobial action can forinstance be determined following the procedures and using the criteriaas outlined in Example 1 below. Typically, evidence of synergisticantimicrobial action is provided at concentrations below the minimumbiocidal concentrations of each of the components when takenindividually. However, it is generally believed that synergistic actioncan still occur when the concentration of one or more of the activecompounds is raised above its minimum biocidal concentration (when takenindividually).

The antimicrobial composition according to the present Inventionpreferably comprises the one or more monosubstituted phenols andterpineol according to the invention at concentrations at which they arecapable of synergistic antimicrobial action. Thus, the concentrations ofthe one or more monosubstituted phenols and of the terpineol in theantimicrobial composition are preferably such that, when the compositionis diluted or dissolved with a suitable medium during use, (e.g. whenwashing hands with water and a composition according to the invention)the concentration in the diluted or dissolved mixture is stillsufficient to be antimicrobially efficacious. That is, to be capable ofsynergistic antimicrobial action, the concentrations of the one or moremonosubstituted phenols and the terpineol in the composition(C_(comp, phenol), and C_(comp, terp), respectively) are preferably suchthat upon application, at a given concentration of the one or moremonosubstituted phenols in the application medium (C_(med, phenol)), theterpineol is available at at least a minimum medium concentration(C_(med, terp)) or vice versa (i.e. such that at a given C_(med, terp),a minimum C_(med, phenol) is available, sufficient to providedsynergistic antimicrobial action). Here, the application medium denotesthe medium in which the antimicrobial action desirably takes place. Forexample, in personal care applications like hand-washing, thecomposition can be a solid soap bar. In that case, C_(comp) refers tothe concentration of the component in the soap bar, whereas C_(med)refers to the concentration in the lather. The minimum and optimumconcentrations can for instance be determined by a protocol as describedfor Example 1 or by one of the standards as detailed below. It isgenerally preferred that the concentrations of the one or moremonosubstituted phenols and the terpineol in the composition accordingto the invention are equal to or higher than the optimal concentrationsin the application medium, because in many typical applications, thecomposition is either used pure or is diluted to form the applicationmedium.

Surprisingly, the synergy between the monosubstituted phenols andterpineol in compositions according to the invention, occurs over a widerange of concentrations and concentration ratios. Depending on factorsincluding the type of antimicrobial composition, its intendedapplication (for instance a hard surface cleaner, a skin cleanser, or ahand sanitiser) different concentration ranges and ratios will bepreferred.

Thus, when for instance antimicrobial action against E. Coli is desired,the data of Example 1 can be used to determine preferable mediumconcentrations C_(med). For example, in case complete microbialinactivation is desired in the particular medium of Example 1 and if themonosubstituted phenols is 2-tert-butylphenol, and C_(med, phenol) isselected as 0.025%(w/v), C_(med, terp) preferably is at least 0.15%(w/v) and vice versa.

Alternatively, the desired antimicrobial effect may be obtained byselecting a ratio of the respective concentrations of the one or moremonosubstituted phenols and the terpineol. In view of theabove-described considerations regarding the intended antimicrobialefficacy and other considerations, including for instance sensoryproperties, solubility, economic considerations, a concentration ratioof monosubstituted phenols to terpineol larger than one is preferred insome applications, whereas a concentration ratio of monosubstitutedphenols to terpineol smaller than one is preferred in others, wherebythe concentrations are expressed in %-wt.

Thus, in case a concentration ratio of monosubstituted phenols toterpineol smaller than one is desired, then the antimicrobialcomposition according to the invention preferably comprises the one ormore monosubstituted phenols and the terpineol in a concentration ratio(monosubstituted phenols:monosubstituted phenols) of between 1:2 and1:12, wherein the concentration is expressed as weight percent.

Alternatively, in case a concentration ratio of monosubstituted phenolsto terpineol larger than one is desired, then the antimicrobialcomposition according to the invention preferably comprises the one ormore monosubstituted phenols and terpineol in an applicableconcentration ratio as specified hereinbelow.

For a number of preferred monosubstituted phenols, the following weightratios are preferred.

In a preferred embodiment of the invention, the synergisticantimicrobial composition comprises (E)-2-(prop-1-enyl)phenol andterpineol. Preferably, a weight ratio of (E)-2-(prop-1-enyl)phenol toterpineol is from 1/0.13 to 1/1.5.

In a preferred embodiment of the invention, the synergisticantimicrobial composition comprises 4-propylphenol and terpineol.Preferably, a weight ratio of 4-propylphenol to terpineol is from 1/0.38to 1/3.

In a preferred embodiment of the invention, the synergisticantimicrobial composition comprises 2-tert-butylphenol and terpineol.Preferably, a weight ratio of 2-tert-butylphenol to terpineol is about1/3.75.

In a preferred embodiment of the invention, the synergisticantimicrobial composition comprises 2-sec-butylphenol and terpineol.Preferably, a weight ratio of 2-sec-butylphenol to terpineol is about1/3.75.

In a preferred embodiment of the Invention, the synergisticantimicrobial composition comprises 3-n-propylphenol and terpineol.Preferably, a weight ratio of 3-n-propylphenol to terpineol is from1/0.19 to 1/3.75, preferably from 1/0.33 to 1/3.75.

In a preferred embodiment of the invention, the synergisticantimicrobial composition comprises 4-n-butylphenol and terpineol.Preferably, a weight ratio of 4-n-butylphenol to terpineol is from 1/0.5to 1/7.5.

In a preferred embodiment of the invention, the synergisticantimicrobial composition comprises 4-pentylphenol and terpineol.Preferably, a weight ratio of 4-pentylphenol to terpineol is from 1/0.17to 1/3.

In a preferred embodiment of the invention, the synergisticantimicrobial composition comprises 4-sec-butylphenol and terpineol.Preferably, a weight ratio of 4-sec-butylphenol to terpineol is from 1/1to 1/5.

In a preferred embodiment of the invention, the synergisticantimicrobial composition comprises 3-tert-butylphenol and terpineol.Preferably, a weight ratio of 3-tert-butylphenol to terpineol is from1/3 to 1/3.75.

In a preferred embodiment of the invention, the synergisticantimicrobial composition comprises 2-hydroxydiphenylmethane andterpineol. Preferably, a weight ratio of 2-hydroxydiphenylmethane toterpineol is from 1/0.05 to 1/1.5, preferably from 1/0.19 to 1/1.5.

In a preferred embodiment of the invention, the synergisticantimicrobial composition comprises 4-hydroxydiphenylmethane andterpineol. Preferably, a weight ratio of 4-hydroxydiphenylmethane toterpineol is from 1/0.06 to 1/1.5, preferably from 1/0.06 to 1/0.13 or1/0.33 to 1/1.5.

In a preferred embodiment of the invention, the synergisticantimicrobial composition comprises 2-cyclopentylphenol and terpineol.Preferably, a weight ratio of 2-cyclopentylphenol to terpineol is from1/0.04 to 1/1, preferably from 1/0.04 to 1/0.15 or 1/0.2 to 1/1.

In a preferred embodiment of the invention, the synergisticantimicrobial composition comprises 4-cyclopentylphenol and terpineol.Preferably, a weight ratio of 4-cyclopentylphenol to terpineol is from1/0.05 to 1/3, preferably from 1/0.19 to 1/3.

A further additional advantage of the present invention is that it isobserved that treatment of a surface with a composition according to theinvention comprising one or more monosubstituted phenols and terpineol,surprisingly enables continued protection of the surface against growthof microbes for a substantial period of time thereafter.

Effect of Including Surfactant

Favourably, compositions suitable in wash-off processes as describedabove include a surfactant for the cleaning action. To the furthersurprise of the inventors, while the surfactant alone does not providethe fast antimicrobial kill at the concentration present in wash offprocesses, it provides for further improvement in extent of reduction inviable microbial counts on the surface in the short period of time whensurfaces are washed with a composition comprising one or moremonosubstituted phenols, terpineol and additionally surfactant. Thus,while surfactant is generally known to be responsible for washing offdirt and also antimicrobial actives used in the composition, in thepresent invention, it provides a highly useful additional benefit inthat it enhances the reduction of viable microbial count in acomposition comprising a combination of monosubstituted phenols andterpineol alone.

However, it was surprisingly found that certain surfactants may reducethe activity of antimicrobial agents according to the invention. Thishappens for instance with cocoyl glycinate and lauroamphoacetate.Generally, surfactants are required in cleaning compositions to obtaingood cleaning results. Since it is inter alia an object of thisinvention to provide antimicrobial cleaning compositions, it thereforealso is an object of this invention to provide monosubstituted phenolscapable of enhanced antimicrobial action upon combination with terpineolin the presence of such surfactants. It was found that in particular2-n-propylphenol, 3-n-propylphenol, 4-n-propylphenol. 4-n-butylphenol,2-tert-butylphenol, 3-tert-butylphenol, 4-tert-butylphenol,2-sec-butylphenol, 4-sec-butylphenol, 3-phenylphenol, 2-benzylphenol,4-benzylphenol, 2-cyclopentylphenol, (E-2-(prop-1-enyl)phenol showenhanced antimicrobial action in combination with terpineol. Thereforethe composition according to the invention preferably comprises one ormore monosubstituted phenols selected from the group consisting of2-n-propylphenol, 3-n-propylphenol, 4-n-propylphenol. 4-n-butylphenol,2-tert-butylphenol. 3-tert-butylphenol. 4-tert-butylphenol,2-sec-butylphenol, 4-sec-butylphenol, 3-phenylphenol, 2-benzylphenol,4-benzylphenol, 2-cyclopentylphenol, and (E)-2-(prop-1-enyl)phenol. Morespecifically, it is preferred that in case the composition according tothe invention comprises a surfactant selected from cocoyl glycinate andlauroamphoacetate, that the monosubstituted phenol is selected from thegroup consisting of 2-n-propylphenol, 3-n-propylphenol,4-n-propylphenol, 4-n-butylphenol, 2-tert-butylphenol,3-tert-butylphenol, 4-tert-butylphenol, 2-sec-butylphenol,4-sec-butylphenol. 3-phenylphenol, 2-benzylphenol 4-benzylphenol,2-cyclopentylphenol, and (E)-2-(prop-1-enyl)phenol.

Method According to the Invention

According to the second aspect, the invention relates to a method ofdisinfecting a surface comprising the steps of

-   -   a. applying a composition according to the invention on to the        surface; and    -   b. removing the composition from the surface.

Preferably, the surface is skin. Thus, for example, a surface like thehands, face, body, or the oral cavity is contacted with the compositionof the invention. If the surface is a surface of a human or animal body,the method preferably is a non-therapeutic method of disinfecting asurface. Alternatively, the surface is any hard surface. Typically, suchhard surfaces are surfaces that commonly require cleaning and preferablyalso require sanitisation or disinfection. Such surfaces may be found inmany household or industrial environments, and may include for examplekitchen and bathroom surfaces, table tops, floors, walls, windows,utensils, cutlery, and crockery. Such surfaces may be made from manydifferent materials, including for instance plastics, wood, metal,ceramics, glass, concrete, marble, and painted surfaces.

The composition may be applied to the surface by any suitable meansknown to the skilled person. For instance, a suitable means may bepouring, dropping, spraying or wiping in case of liquid compositions.

Preferably, the method includes diluting or dissolving the compositionwith a suitable solvent, preferably water, before or whilst applying thecomposition to the surface. Such dissolving is preferred in particularin case the composition is a solid composition. Alternatively, solidcompositions may also be directly spread, rubbed, or sprayed, e.g. inthe form of a powder.

The method according to the first aspect of the present invention alsoincludes the step of removing the composition from the surface. Here,removing the composition also encompasses partially removing thecomposition, because traces of the composition may remain on thesurface. In many typical situations, such as washing of the skin orhard-surface cleaning, it is acceptable or sometimes even desirable ifpart of the composition—in particular certain active ingredients—remainson the surface. Therefore, step b preferably involves removing at least5%, more preferably at least 10%, even more preferably at least 25%,still more preferably at least 50% and yet more preferably at least 75%of the composition by weight. Preferably, the step of removing thecomposition comprises rinsing the surface with a suitable solvent orwiping the surface with a suitable wipe, more preferably, this stepconsists of rinsing the surface with a suitable solvent or wiping thesurface with a suitable wipe. Alternatively, the removal step can alsoinclude evaporation of part of the composition, for example when thecomposition comprises volatile components, e.g. solvents.

A suitable medium for rinsing the surface is water but it could also befor example a mixture of water and alcohol. It is then rinsed preferablywith sufficient amounts of water after a pre-determined period of timeto remove any visible or sensory residue of the composition.Alternatively, an alcohol wipe or a water/alcohol impregnated wipe maybe used to wipe the surface to be visibly free of the anti-microbialcomposition. The step of removing the composition (e.g. by rinsing orwiping the surface) is preferably started less than 5 minutes, morepreferably less than 2 minutes, even more preferably less than 1 minute,still more preferably less than 30 seconds and yet more preferably lessthan 20 seconds after commencement of the step of applying thecomposition on the surface, because of the surprisingly fastantimicrobial action of the compositions according to the presentinvention. Even though partial microbial kill may be almostinstantaneous upon application of the composition according to theinvention, it is preferred that the step of removing the compositionfrom the surface is started out at least 5 seconds, preferably at least10 seconds, more preferably at least 15 seconds after commencement ofthe step of applying the composition on the surface, in order to effectoptimal antimicrobial action. Combinations of these times into timeintervals are preferred too. Therefore, it is particularly preferredthat the step of removing the composition from the surface (i.e. step b)is started between 2 minutes and 5 seconds, more preferably between 1minute and 10 seconds, even more preferably between 30 and 10 secondsand still more preferably between 20 and 15 seconds after commencementof the step of applying the composition on the surface (i.e. step a).

Disinfection Time

These times between applying the composition and rinsing or wiping arepreferably related to the disinfection time, in order to ensure optimalcleansing and sanitising of the surface. Therefore, the inventionpreferably relates to a method, wherein the disinfection time T of saidmethod is less than 300 seconds, preferably less than 60 seconds, andmore preferably less than 15 seconds; wherein T is defined as the timethat elapses from the moment of adding the composition to a microbialculture until the number of microbes per unit volume of the culture isreduced by a factor of 100 000; and wherein the initial number ofmicrobes preferably exceeds about 100 000 000 microbes per millilitreand wherein the composition is preferably a liquid composition.

The disinfecting action of the method (as may be expressed in terms ofthe disinfection time T) is preferably determined according to theprotocol of Example 1 as described hereinafter. This test relates to astandardised test environment in which the microbial culture is kept insuspension. A similarly suitable test Is the standard suspension methoddescribed in European Standard EN1276, with the proviso that thedisinfection time is adapted to suit the above criteria as will be clearto a person skilled in the art. Alternatively, one of the test methodsas described in WO 2010/046238 may for instance be applied to establishthe disinfecting action.

Such test methods may preferably also be used by the skilled person todetermine the optimal concentrations of the one or more monosubstitutedphenols and the terpineol in an antimicrobial composition according tothe present invention.

Alternatively, since the method is directed towards surfacedisinfection, the disinfection time may also be determined by testmethods involving a surface. Therefore, the invention preferably relatesto a method according to the present invention, wherein the surfacedisinfection time T2 of said method is less than 60 seconds, preferablyless than 15 seconds, wherein T2 is defined as the time starting fromthe moment of applying the composition to the surface to be disinfectedafter which the number of microbes per unit area is reduced by a factorof 10000 (i.e. a 4 log reduction), wherein the initial number ofmicrobes preferably exceeds 10³, more preferably 10⁵, and even morepreferably 10⁷ microbes per square centimetre. Such tests may forinstance be performed as described in WO 20101046238, or as described inEuropean Standards EN 13697:2001 and EN 1500:1997.

Use According to the Invention

The invention preferably provides for non-therapeutic benefits. Thus,for instance, the invention relates to use of an antimicrobialcomposition according to the present invention for faster reduction inviable microbial count.

Thus, according to the third aspect of the invention, there is provideduse of a composition according to the invention for improved hygiene.Such use relates for example to use of an antimicrobial compositioncomprising the one or more monosubstituted phenols, terpineol and acarrier, for reduction in viable microbial count, preferably fastreduction of viable microbial count. Thus, such use preferably is use ina method for disinfection. Fast reduction in viable microbial counttherefore preferably relates to use for disinfection whereby thedisinfection time is less than 300 seconds, preferably less than 60seconds, and more preferably less than 15 seconds. Here, thedisinfection is preferably defined similar to the disinfection times Tand T2 as described above.

Thus, there is provided use of a composition according to the inventionfor improved hygiene of surfaces of the human body. Such surfacesInclude e.g. skin, hands and the oral cavity. According to a preferredaspect, the invention relates to use of a composition according to theinvention for improved hand hygiene. According to another preferredaspect, the invention relates to use of a composition according to theinvention for improved oral hygiene.

The microbicide compositions of the present invention can be used toinhibit the growth of microorganisms by introducing a microbicidallyeffective amount of the compositions onto, into or at a locus subject toattack. For instance, in the field of institutional and industrialapplications, suitable loci include, for example: industrial processwater Including electrocoat deposition systems, cooling towers and airwashers; gas scrubbers; wastewater treatment; ornamental fountains;reverse osmosis filtration; ultrafiltration; ballast water; evaporativecondensers and heat exchangers: pulp and paper processing fluids andadditives; mineral slurries; starch; plastics; emulsions; dispersions:paints; latices; coatings, such as varnishes; construction products,such as mastics, caulks, and sealants; construction adhesives, such asceramic adhesives, carpet backing adhesives, and laminating adhesives;industrial or consumer adhesives; photographic chemicals; printingfluids; household and institutional products used in restaurants,healthcare facilities, schools, food processing facilities and farmsincluding, cleaners, sanitizers and disinfectants, wipes, soaps,detergents, floor polishes and laundry rinse water; cosmetics;toiletries; shampoos; metalworking fluids; conveyor lubricants;hydraulic fluids; leather and leather processing products; textiles;textile and textile processing products; wood and wood processingproducts, such as plywood, chipboard, wallboard, flakeboard, laminatedbeams, oriented strandboard, hardboard, and particleboard; oil and gasprocessing fluids such as injection fluids, fracture fluids, drillingmuds and produced water; fuel transportation and storage systems:agriculture adjuvant preservation; surfactant preservation: medicaldevices; diagnostic reagent preservation; food preservation, such asplastic or paper food wrap; food, beverage, and industrial processpasteurizers; toilet bowls; recreational water; pools; and spas.

Preferably, the microbicidal compositions of the present invention areused to inhibit the growth of microorganisms at a locus selected fromone or more of mineral slurries, pulp and paper processing fluids andadditives, starch, emulsions, dispersions, paints, latices, coatings,construction adhesives (such as ceramic adhesives), carpet backingadhesives, photographic chemicals, printing fluids, household andinstitutional products such as cleaners, sanitizers, disinfectants,wipes, cosmetics, toiletries, shampoos, soaps, detergents, floorpolishes, laundry rinse water, metal working fluids, textile products,wood and wood products, agriculture adjuvant preservation, surfactantpreservation, diagnostic reagent preservation, food preservation, food,beverage, and industrial process pasteurizers and oil and gas processingfluids.

Fields of Use

The composition according to the invention can in view of the above beapplied for disinfection, reduction in viable microbial count orimproved hygiene, especially at a surface. In preferred embodiments, thecomposition is particularly suited for application to the skin. Forexample, a surface like the hands, face, body, or the oral cavity cansuitably be contacted with the composition of the invention. In otherpreferred embodiments, the surface is any hard surface. Typically, suchhard surfaces are surfaces that commonly require cleaning and often alsorequire sanitisation or disinfection. Such surfaces can be found in manyhousehold or industrial environments, and can include for examplekitchen and bathroom surfaces, table tops, floors, walls, windows,utensils, cutlery, and crockery. Such surfaces can be made from manydifferent materials, for instance plastics, wood, metal, ceramics,glass, concrete, marble, and painted surfaces. In other preferredembodiments, the compositions can be used for such disinfection,reduction in viable microbial count or improved hygiene at loci otherthan the surfaces as described hereinbefore.

In preferred embodiments, the invention relates to compositionsaccording to the invention for use as or incorporation in home careproducts and personal care products. More preferably, this embodiment ofthe invention relates to a composition according to the invention whichis a home care product or a personal care product.

A “home care product” is a product for the treatment, cleaning, caringor conditioning of the home or any of its contents. The foregoingincludes, but is not limited to, compositions, products, or combinationsthereof relating to or having use or application in the treatment,cleaning, cleansing, caring or conditioning of surfaces, furniture andatmosphere of the home and household contents, such as clothes, fabricsand/or cloth fibres and the manufacture of all of the foregoingproducts. A “personal care product” is a product for the treatment,cleaning, caring or conditioning of the person. The foregoing includes,but is not limited to, chemicals, compositions, products, orcombinations thereof relating to or having use or application in thetreatment, cleaning, cleansing or conditioning of the person (includingin particular the skin, hair and oral cavity), and the manufacture ofall the foregoing. Home care products and personal care products are forexample products marketed under mass market brands, non-limitingexamples being soap bars, deodorants, shampoos, and home surfacesanitisers/disinfectants.

Another preferred embodiment of the invention relates to compositionsaccording to the invention for use as or incorporation in industrialand/or institutional products. More preferably, this embodiment of theinvention relates to a composition according to the invention which isan industrial and/or an institutional product. Industrial andinstitutional products are for example products being marketed underprofessional brands, non-limiting examples being for industrial,institutional, janitorial, and medical cleaning, cleaning-in-place, foodservices, veterinary, and agricultural products. Industrial and/orinstitutional products also include products for cleaning of the person(such as hand sanitisers) for medical offices, hospitals and/or otherinstitutions.

In another preferred embodiment, the invention also relates to a methodor use according to the invention involving home care products orpersonal care products. For example, the method according to theinvention—which comprises application of a composition according to theInvention in step a—can be a method wherein that composition is acomposition for use as or incorporation in home care products andpersonal care products as described hereinabove. Similarly, in anotherpreferred embodiment, the invention also relates to a method or useaccording to the invention involving industrial and/or institutionalproducts. For example, the method according to the invention—whichcomprises application of a composition according to the invention instep a—can be a method wherein that composition is a composition for useas or incorporation in industrial and/or institutional products asdescribed hereinabove.

Products and/or methods for use in the home care or personal care fieldare generally distinct from products and/or methods for use in theindustrial and/or institutional field. Thus, for example, a product thatis marketed as a home or personal care product will generally not bemarketed as a product for industrial and/or institutional use and viceversa. Therefore, certain embodiments of the present invention, whencarried forth into practice, will relate to the one field, but not theother.

EXAMPLES

The invention is illustrated by the following non-limiting examples.

Example 1 Assessment of Antimicrobial Efficacy Materials

Monosubstituted phenols were purchased as fine chemicals from supplierssuch as Sigma Aldrich, Alfa Aesar and TCI Fine Chemicals.

A terpineol mixture comprising ca 88 wt-% of (S)-alpha-terpineol, and 12wt-% of gamma-terpineol was purchased from Sigma Aldrich and usedthroughout the examples (being referred to as alpha-terpineol orterpineol) unless specified otherwise.

General Method for Assessment of Antimicrobial Synergy

The efficacies of antimicrobial agents can be usefully compared bydetermining the Minimum Biocidal Concentration (MBC). The MBC is definedas the lowest absolute concentration of the particular active thatprovides complete kill (zero bacterial growth). The differing behavioursof inhibitory antimicrobtals in Isolation and mixtures have been widelyexplored using the concept of the Fractional Concentration andFractional Inhibitory Concentration (FIC). See for instance J R WLambert and R Lambert, J. Appl. Microblol 95, 734 (2003); T. Jadavji. CG Prober and R Cheung. Antimicrobial Agents and Chemotherapy 26, 91(1984), and WO 2004/006876. These parameters can be defined as follows:

${{FC}\left( {{component}\mspace{14mu} a} \right)} = \frac{{Concentration}\mspace{14mu} {of}\mspace{14mu} {component}\mspace{14mu} a\mspace{14mu} {tested}\mspace{14mu} {in}\mspace{14mu} {the}\mspace{14mu} {mixture}}{{MIC}\left( {{component}\mspace{14mu} a\mspace{14mu} {tested}\mspace{14mu} {as}\mspace{14mu} a\mspace{14mu} {single}\mspace{14mu} {active}} \right)}$${{FIC}\left( {{component}\mspace{14mu} a} \right)} = \frac{{MIC}\left( {{component}\mspace{14mu} a\mspace{14mu} {tested}\mspace{14mu} {in}\mspace{14mu} {the}\mspace{14mu} {mixture}} \right)}{{MIC}\left( {{component}\mspace{14mu} a\mspace{14mu} {tested}\mspace{14mu} {as}\mspace{14mu} a\mspace{14mu} {single}\mspace{14mu} {active}} \right)}$

By analogy the Fractional Biocidal Concentration (FBC) is given by:

${{FBC}\left( {{component}\mspace{14mu} a} \right)} = \frac{{MBC}\left( {{component}\mspace{14mu} a\mspace{14mu} {tested}\mspace{14mu} {in}\mspace{14mu} {the}\mspace{14mu} {mixture}} \right)}{{MBC}\left( {{component}\mspace{14mu} a\mspace{14mu} {tested}\mspace{14mu} {as}\mspace{14mu} a\mspace{14mu} {single}\mspace{14mu} {active}} \right)}$

The interactions between antimicrobials can be additive, synergistic orpossibly antagonistic depending on whether the efficacy of thecombination is equivalent to, greater than or less than that obtainedfor the same total concentration of the individual components whentested alone.

These relationships can be expressed mathematically by summing thefractional MBC values for all the components present in the mixture togive the “fractional biocidal index”:

ΣFBC=FBC _((component 1)) +FBC _((component 2)) +FBC _((component 3))+ .. . etc

such that

-   -   ΣFBC≧1 corresponds to additive or antagonistic bactericidal        activity    -   ΣFBC<1 corresponds to synergistic bactericidal activity

Experimental Method

Antimicrobial efficacy is tested against a representative pathogenicbacterial organism, Gram negative Escherichia coli. Concentrations ofactives are expressed in terms of the percentage weight/volume (% w/v)throughout Example 1.

Bacterial Stock

An overnight culture of Escherichia coli (10536 strain) was prepared in50 ml total volume of TSB broth, grown for ca. 18 hrs at 37° C. andshaken at 150 rpm. 1 ml of this overnight E. coli culture wastransferred to 50 ml of fresh TSB broth and incubated at 37° C. at 150rpm for ca. 4 hours. This culture was separated into equal volumes andcentrifuged at 4000 rpm for 15 minutes, washed with sterile saline(0.85% NaCl), centrifuged once more and re-suspended in saline to give afinal concentration of 0.8 OD₆₂₀ equivalent to about 10⁸ cells permillilitre for this particular organism. Here, OD₆₂₀ indicates theabsorbance of a sample in a cuvette of 1.0 cm path length at awavelength of 620 nm. This bacterial stock was used for assaying againstantimicrobial actives (in triplicate).

Protocol

The following assay describes the testing of 8 materials using 6dilutions across half of a 96-well micro titre plate (MTP). Using thisapproach it is possible to assay 16 actives (without replicates) withone full dilution plate, replicating this set up in two halves of theplate columns, 1-6 and 7-12.

1M solutions of the test actives were prepared in dimethylsulphoxide(DMSO). Stock solutions of the actives at 1.11 times the desired finalconcentration were prepared by diluting the DMSO solutions in water, sothat for example a 0.89% w/v solution was prepared for a desired “intest” concentration of 0.8% w/v in order to allow for the furtherdilution of the active when the bacterial suspension is added (dilutionfrom 270 μl to 300 μl), as described below.

Aliquots (270 μl) of the materials at 1.11 times the final concentrationwere dispensed into the wells of the MTP along one column (A1-H1). ThisMTP was labelled as the “Screening plate”.

In another MTP, labelled as the “Dilution plate”, 270 μl of D/Eneutralising solution from DIFCO Composition was added to column 1. Thecomposition of the neutralising solution was as follows: pancreaticdigest of casein, 5.0 g/L; Yeast Extract, 2.5 g/L; Dextrose, 10 g/L,sodium thioglycollate, 1.0 g/L, sodium thiosulphate, 6.0 g/L; sodiumbisulphite, 2.5 g/L; Polysorbate 80, 5.0 g/L; lecithin 7.0 g/L;bromocresol purple, 0.02 g/L with a pH in the range 7.6±0.2.

270 μl of tryptone diluent solution was added to all the remaining wellsof the Dilution MTP (columns 2-6).

Bacterial stock (30 μl) was then added to the prepared 270 μl of thesolution of actives in the Screening Plate and mixed, using amultichannel pipette with 8 tips to aspirate and dispense the samevolume of bacterial stock in parallel to 8 wells in rows A-H. After acontact time of 15 seconds, the mixtures were quenched by transferring30 μl volumes of the mixtures into the 270 μl D/E neutralising solutionin the prepared dilution plate, using aspiration to mix. After exactly 5minutes in the DIE neutralising solution, 30 μl volumes were transferredfrom column 1 to column 2 of the Dilution MTP and mixed, beforetransferring further 30 μl volumes from column 2 into column 3. Thisprocess was repeated serially diluting the bacteria across the plate tocolumn 6.

30 μl volumes from each well in the Dilution MTP were transferred ontopre-labelled segment of Tryptone Soya Agar (TSA) plates starting fromthe lowest bacterial concentration (highest dilution, column 6) to thehighest bacterial concentration (column 1). The TSA plates were allowedto stand for ca. 2 hours so that the 30 μl inocula spots could dry andthe plates were then inverted and incubated overnight at 37° C. beforeenumerating the bacterial colonies at the labelled dilutions todetermine the effects of the actives on bacterial growth.

Calculation of Results

Mean bacterial survival numbers N_(MBS) (expressed in Log CFU/ml) areobtained by first determining the segment of the TSA plate where thenumber of bacterial colonies is countable. From the colony number inthis segment. N_(MBS) is calculated by the formula:

N _(MBS)=log {N _(col)·10^(DF)·100/3}

Here. N_(col) is the colony count, and DF is the dilution factor takenfrom the MTP-well corresponding to the TSA plate segment (i.e. DF mayrange from 1 for the quench, to 6 for the highest dilution). The factor100/3 is a conversion factor from the volume of the inocula spot to onemillilitre.

Every assay test was performed in triplicate. The reported meanbacterial survival results are the average of such a triplet, the erroris the corresponding standard deviation.

Thus, a value of N_(MBS) of about 7 corresponds to a count of about 3colonies from the fifth dilution well, i.e. with DF=5. Such a count ofabout 7 is generally observed when bacteria are exposed to non-biocidalmaterials. In case no surviving colonies are observed in any segment ofthe TSA plate, this is interpreted as complete kill and a value ofN_(MBS)=0 is reported.

Validation

All test results were validated by running every test assay in parallelwith four control experiments on the same MTP. All control experimentsare executed exactly according to the above protocol, but with thefollowing active ingredients:

-   -   A 0.025% (w/v) thymol    -   B 0.15% (w/v) alpha-terpineol    -   C 0.025% (w/v) thymol+0.15% (w/v) alpha-terpineol    -   D no active component

The control experiments A, B and D validate a test assay by not showingbacterial kill, whereas control experiment C, comprising a synergisticcombination of thymol and alpha-terpineol according to WO 2010/046238 A1validates a test assay by showing complete bacterial kill.

A reference experiment according to the above protocol, but withoutactive component, showed that DMSO does not affect bacterial growth atthe concentrations present in the test solutions in this protocol (<5%(w/v)), as can be seen in Table 4.

TABLE 4 DMSO in water Mean bacterial survival Standard (% w/v) [logCFU/ml] deviation 4.5 8.2 0.1 3.6 8.4 0.2 2.7 8.2 0.1 1.8 8.5 0.2 0.98.6 0.1 0.0 8.5 0.1

Results

The above method was applied to asses the antibacterial efficacy of themonosubstituted phenols according to the invention. Table 5 shows theantibacterial activities of the monosubstituted phenols, both alone andin conjunction with terpineol.

TABLE 5 Antibacterial activities of thymol, and monosubstituted phenolsalone and in combination with terpineol Mono- substituted phenolConcentration N_(MBS) concentration of terpineol [log Standard ExampleC_((phenol))(% w/v) C_(TERP)(% w/v) CFU/ml] deviation 1:1 0.075% thymol0 0 0 1:2* 0.05% thymol 0 0 0 1:3* 0.025% thymol 0 >7 0.1 1:4* 0 0.5%alpha- 0 0 terpineol 1:5* 0 0.4% alpha- 0 0 terpineol 1:6* 0 0.3% alpha-7 0.2 terpineol 1:7* 0 0.15% alpha- 7 0.2 terpineol 1:8* 0.075% 4-n- 0 00 propylphenol 1:9* 0.0375% 4-n- 0 7.8 0.2 propylphenol 1:10 0.0375%4-n- 0.15% alpha- 0 0 propylphenol terpineol 1:11 0.025% 4-n- 0.15%alpha- 0 0 propylphenol terpineol 1:12* 0.025% 4-n- 0 0 0 butylphenol1:13* 0.0125% 4- 0 7.0 0.7 butylphenol 1:14 0.0125% 4-n- 0.15% alpha- 00 butylphenol terpineol 1:15* 0.025% 4-n- 0 0 0 pentylphenol 1:16*0.0125% 4- 0 6.6 0.2 pentylphenol 1:17 0.0125% 4- 0.15% alpha- 0 0pentylphenol terpineol 1:18* 0.05% 2-tert- 0 0 0 butylphenol 1:19*0.025% 2-tert- 0 7.5 0.1 butylphenol 1:20 0.025% 2-tert- 0.15% alpha- 00 butylphenol terpineol 1:21* 0.08% 3-tert- 0 0 0 butylphenol 1:22*0.05% 3-tert- 0 7.6 0.5 butylphenol 1:23 0.04% 3-tert- 0.15% alpha- 0 0butylphenol terpineol 1:24* 0.05% 2-sec- 0 0 0 butylphenol 1:25* 0.025%2-sec- 0 7.5 0.1 butylphenol 1:26 0.025% 2-sec- 0.15% alpha- 0 0butylphenol terpineol 1:27* 0.08% 4-sec- 0 0 0 butylphenol 1:28* 0.05%4-sec- 0 4.1 3.6 butylphenol 1:29* 0.025% 4-sec- 0 7.6 0.2 butylphenol1:30 0.025% 4-sec- 0.15% alpha- 0 0 butylphenol terpineol 1:31* 0.1% 2-0 0 0 cyclopentylphenol 1:32* 0.08% 2- 0 3.4 0.3 cyclopentylphenol 1:33*0.05% 2- 0 7.5 0.5 cyclopentylphenol 1:34 0.025% 2- 0.15% alpha- 0 0cyclopentylphenol terpineol 1:35* 0.08% 4- 0 0 0 cyclopentylphenol 1:36*0.05% 4- 0 7.1 0.3 cyclopentylphenol 1:37 0.04% 4- 0.15% alpha- 0 0cyclopentylphenol terpineol 1:38* 0.15%(E)-2- 0 0 0 (prop-1- enyl)phenol1:39* 0.075% (E)-2- 0 6.9 0.1 (prop-1- enyl)phenol 1:40 0.075% (E)-2-0.15% alpha- 0 0 (prop-1- terpineol enyl)phenol 1:41* 0.05% 2- 0 0 0benzylphenol 1:42* 0.025% 2- 0 7.1 0.3 benzylphenol 1:43 0.025% 2- 0.15%alpha- 0 0 benzylphenol terpineol 1:44* 0.05% 4- 0 0 0 benzylphenol1:45* 0.025% 4- 0 3.8 0.2 benzylphenol 1:46 0.025% 4- 0.15% alpha- 0 0benzylphenol terpineol 1:47* 0.075% 2- 0.15% alpha- 8.1 0.4 methylphenolterpineol 1:48* 0.025% 2- 0.15% alpha- 7.9 0.4 methylphenol terpineol1:40* 0.025% 4- 0.15% alpha- 6.8 0.4 hexylphenol terpineol 1:50* 0.025%4- 0.15% alpha- 8.1 0.5 heptylphenol terpineol 1:51* 0.025% eugenol0.15% alpha- 7.8 0.2 (4-allyl-2- terpineol methoxy-phenol) *Examplesmarked with an asterisk (*) are comparative examples

COMPARATIVE EXAMPLES

Determination of the parameter ΣFBC, which is used as measure of thesynergistic antimicrobial action of compositions according to thepresent invention, requires determination of the Minimum BiocidalConcentrations (MBCs) of the relevant actives first. As described above,the MBC for an active can be defined as the lowest concentration of theactive that provides zero bacterial survival in the particular medium.Data for examples (1:1) to (1:3) demonstrate that the MBC value forthymol is 0.05% (w/v). For alpha-terpineol, compositions (1:4) to (1:7),show that the MBC is 0.4% w/v. The same analysis has been carried outfor selected monosubstituted phenols and is summarised in Table 6 below.These MBC values constitute the upper boundaries to the respective MBCsin the particular medium used in these examples.

TABLE 6 Minimum biocidal concentrations of antimicrobial componentsComponent MBC (% w/v) Thymol 0.05 alpha-terpineol 0.4 4-n-propylphenol0.075 4-n-butylphenol 0.025 4-pentylphenol 0.025 2-tert-butylphenol 0.053-tert-butylphenol 0.08 2-sec-butylphenol 0.05 4-sec-butylphenol 0.082-cyclopentylphenol 0.1 4-cyclopentylphenol 0.08(E)-2-(prop-1-enyl)phenol 0.15 2-benzylphenol 0.05 4-benzylphenol 0.05

It is clear from the data in Table 6 that the monosubstituted phenolsaccording to the present invention are antimicrobially efficacious.

Synergistic Interactions

The tested combinations of the selected monosubstituted phenols withterpineol provide complete bacterial kill in the examples (1:10),(1:11), (1:14), (1:17), (1:20), (1:23), (1:26), (1:30), (1:34), (1:37),(1:40), (1:43), and (1:46). Using the MBC values listed in Table 6above, the fractional MBC values for the components present in thesemixtures and the experimental ΣFBC of the compositions can be calculatedin order to discriminate between combinations providing evidence ofsynergistic effects, as opposed to additive biocidal effects. Theresults from this analysis are given in Table 7.

TABLE 7 Extent of synergistic interactions between binary compoundmixtures for compositions providing complete bacterial kill Evi-monosubstituted phenol terpineol dence MBC % MBC % of Syn- compound Ex.(w/v) FBC^(a) (w/v) FBC^(b) ΣFBC ergy^(c) 4-n- 1:10 0.075 0.5 0.4 0.380.88 Yes propylphenol 4-n- 1:11 0.075 0.33 0.4 0.38 0.71 Yespropylphenol 4-n- 1:14 0.025 0.5 0.4 0.38 0.88 Yes butylphenol 4-n- 1:170.025 0.5 0.4 0.38 0.88 Yes pentylphenol 2-tert- 1:20 0.05 0.5 0.4 0.380.88 Yes butylphenol 3-tert- 1:23 0.08 0.5 0.4 0.38 0.88 Yes butylphenol2-sec- 1:26 0.05 0.5 0.4 0.38 0.88 Yes butylphenol 4-sec- 1:30 0.08 0.310.4 0.38 0.69 Yes butylphenol 2- 1:34 0.1 0.25 0.4 0.38 0.63 Yescyclopentyl- phenol 4- 1:37 0.08 0.5 0.4 0.38 0.88 Yes cyclopentyl-phenol (E)-2- 1:40 0.15 0.5 0.4 0.38 0.88 Yes (prop-1- enyl)phenol 2-1:43 0.05 0.5 0.4 0.38 0.88 Yes benzylphenol 4- 1:46 0.05 0.5 0.4 0.380.88 Yes benzylphenol ^(a)FBC of phenol: C_(phenol)/MBC_(phenol) ^(b)FBCof terpineol: C_(terpineol)/MBC_(terpineol) ^(c)Criterion for synergy:(ΣFBC <1)

For Examples for which the ΣFBC value is below 1 in Table 7 provideevidence for synergistic interactions, according to the set criteria.Therefore, these examples show how the antimicrobial efficacy ofterpineol and the monosubstituted phenols according to invention areenhanced when they are applied together. Such synergies allow forreductions in the concentrations of the antimicrobials required toachieve complete kill. For example 0.4% w/v terpineol is required toachieve complete bacterial kill when tested in isolation but this can bereduced 2.7-fold to 0.15% (w/v) when used in combination with 0.025% w/vof 2-tert-butylphenol or 0.025% w/v of 2-cyclopentylphenol.

COMPARATIVE EXAMPLES

The comparative examples (1:47) to (1:51) show that compositionscomprising terpineol and phenolic compounds that are not compoundsaccording to the present invention (2-methylphenol, 4-hexylphenol,4-heptylphenol and eugenol) at concentrations comparable to those in theexamples according to the invention do not give rise to fastantimicrobial action.

Example 2

In this Example, a wide range of combinations of chemicals was tested byconducting high resolution MBC assays of monosubstituted phenols in thepresence of various concentrations of terpineol. The materials weresourced in the same way as for Example 1. Synergy tests were conductedusing standard microtiter plate assays with phosphate buffer containing35% dipropylene glycol (DPG). High resolution MBCs were determined byadding varying amounts of microbicide to one column of a microtiterplate and doing subsequent ten-fold dilutions using an automated liquidhandling system to obtain a series of endpoints ranging from 0.002% to1% of the test compound. The MBC plate was inoculated one column at atime with the test microorganism. An aliquot of the inoculated well wastransferred at 15 seconds to a plate containing a neutralizing agent(D/E Neutralizing Broth), mixed and held for 5 minutes before beingtransferred to a growth plate containing trypticase soy broth (TSB). TheTSB plate was incubated at 37° C. and read for the presence/absence ofgrowth at 24 hours. The lowest level tested that provided complete kill(as evidenced by lack of growth on the microtitre plate) of the testorganisms in 15 seconds is defined as the minimum biocidal concentration(MBC) throughout Example 2.

The synergy of the combinations of the present invention was determinedagainst a the same bacterium as in Example 1, Escherichia coli (E.coli—ATCC #10536), at a concentration of approximately 1×10⁸ bacteriaper mL. This microorganism is representative of natural contaminants inmany consumer and industrial applications. The plates were visuallyevaluated for microbial growth (turbidity) to determine the MBC after 24hours incubation time at 37° C.

The test results for demonstration of synergy of the combinations of thepresent invention are shown below in the Tables 8 to 21. Each of thesetables shows the specific combinations of two components; resultsagainst the microorganism tested; the end-point activity in weight %measured by the MBC for the first component alone (monosubstitutedphenol, MBC_(A)), for the second component alone (terpineol, MBC_(B)),for the first component in the mixture (C_(a)) and for the secondcomponent in the mixture (C_(b)); the calculated ΣFBC value; and therange of synergistic ratios for each combination tested (first componentto second component or A/B) against the particular microorganism.

Data in the tables below include the range of ratios that were found tobe synergistic. (Data which were collected outside of the synergisticranges are not reported.) These data demonstrate that certaincombinations of monosubstituted phenols according to the presentinvention and terpineol show more enhanced control over themicroorganisms than would be expected if the combinations were additiverather than synergistic.

TABLE 8 First Component (A) = (E)-2-(prop-1-enyl)phenol Second Component(B) = terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli10536 0.8 0 1.00 0.8 0.025 1.04 1 to 0.03 0.8 0.05 1.08 1 to 0.06 0.60.075 0.88 1 to 0.13 0.6 0.1 0.92 1 to 0.17 0.2 0.3 0.75 1 to 1.5 0.30.3 0.88 1 to 1 0 0.6 1.00

The ratios of (E)-2-(prop-1-enyl)phenol to terpineol tested ranged from1/0.025 to 1/400. The synergistic ratios of (E)-2-(prop-1-enyl)phenol toterpineol ranged from 1/0.13 to 1/1.5.

TABLE 9 First Component (A) = 4-propylphenol Second Component (B) =terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli 10536 0.30 1.00 0.3 0.025 1.04 1 to 0.08 0.3 0.05 1.08 1 to 0.17 0.2 0.075 0.79 1to 0.38 0.3 0.1 1.17 1 to 0.33 0.1 0.3 0.83 1 to 3 0 0.6 1.00

The ratios of 4-propylphenol to terpineol tested ranged from 1/0.025 to1/400. The synergistic ratios of 4-propylphenol to terpineol range from1/0.38 to 1/3.

TABLE 10 First Component (A) = 2-tert-butylphenol Second Component (B) =terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli 10536 0.20 1.00 0.2 0.025 1.04 1 to 0.13 0.2 0.05 1.08 1 to 0.25 0.2 0.075 1.13 1to 0.38 0.2 0.1 1.17 1 to 0.5 0.08 0.3 0.90 1 to 3.75 0 0.6 1.00

The ratios of 2-tert-butylphenol to terpineol tested ranged from 1/0.025to 1/400. The synergistic ratio of 2-tert-butylphenol to terpineol is1/3.75.

TABLE 11 First Component (A) = 2-sec-butylphenol Second Component (B) =terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli 10536 0.20 1.00 0.2 0.025 1.04 1 to 0.13 0.2 0.05 1.08 1 to 0.25 0.2 0.075 1.13 1to 0.38 0.2 0.1 1.17 1 to 0.5 0.08 0.3 0.90 1 to 3.75 0 0.6 1.60

The ratios of 2-sec-butylphenol to terpineol tested ranged from 1/0.025to 1/400. The synergistic ratio of 2-sec-butylphenol to terpineol is1/3.75.

TABLE 12 First Component (A) = 2-n-propylphenol Second Component (B) =terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli 10536 0.30 1.00 0.6 0.025 2.04 1 to 0.04 0.2 0.05 0.75 1 to 0.25 0.3 0.075 1.13 1to 0.25 0.3 0.1 1.17 1 to 0.33 0.1 0.3 0.83 1 to 3 0 0.6 1.00

The ratios of 2-n-propylphenol to terpineol tested ranged from 1/0.025to 1/350. The synergistic ratios of 2-n-propylphenol to terpineol rangefrom 1/0.25 to 1/3.

TABLE 13 First Component (A) = 3-n-propylphenol Second Component (B) =terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli 10536 0.050 1.00 0.8 0.025 1.64 1 to 0.03 0.5 0.05 1.08 1 to 0.10 0.3 0.075 0.73 1to 0.25 0.4 0.075 0.93 1 to 0.19 0.3 0.1 0.77 1 to 0.33 0.4 0.1 0.97 1to 0.25 0.08 0.3 0.66 1 to 3.75 0.1 0.3 0.70 1 to 3 0.2 0.3 0.90 1 to1.5 0 0.6 1.00

The ratios of 3-n-propylphenol to terpineol tested ranged from 1/0.025to 1/400. The synergistic ratios of 3-n-propylphenol to terpineol rangefrom 1/0.19 to 1/3.75.

TABLE 14 First Component (A) = 4-n-butylphenol Second Component (B) =terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli 10536 0.20 1.00 0.2 0.025 1.04 1 to 0.13 0.1 0.05 0.58 1 to 0.5 0.1 0.075 0.63 1to 0.75 0.1 0.1 0.67 1 to 1 0.04 0.3 0.70 1 to 7.5 0.05 0.3 0.75 1 to 60.06 0.3 0.80 1 to 5 0.08 0.3 0.90 1 to 3.75 0 0.6 1.00

The ratios of 4-n-butylphenol to terpineol tested ranged from 1/0.025 to1/400. The synergistic ratios of 4-n-butylphenol to terpineol range from1/0.5 to 1/7.5.

TABLE 15 First Component (A) = 4-pentylphenol Second Component (B) =terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli 10536 1.00 1.00 1 0.025 1.04 1 to 0.03 2 0.05 2.08 1 to 0.03 2 0.075 2.13 1 to0.04 0.4 0.1 0.57 1 to 0.25 0.5 0.1 0.67 1 to 0.20 0.6 0.1 0.77 1 to0.17 0.1 0.3 0.60 1 to 3 0.2 0.3 0.70 1 to 1.5 0 0.6

The ratios of 4-pentylphenol to terpineol tested ranged from 1/0.025 to1/400. The synergistic ratios of 4-pentylphenol to terpineol range from1/0.17 to 1/3.

TABLE 16 First Component (A) = 4-sec-butylphenol Second Component (B) =terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli 10536 0.20 1.00 0.2 0.025 1.04 1 to 0.13 0.2 0.05 1.08 1 to 0.25 0.2 0.075 1.13 1to 0.38 0.1 0.1 0.67 1 to 1 0.06 0.3 0.80 1 to 5 0.08 0.3 0.90 1 to 3.750 0.6 1.00

The ratios of 4-sec-butylphenol to terpineol tested ranged from 1/0.025to 1/400. The synergistic ratios of 4-sec-butylphenol to terpineol rangefrom 1/1 to 1/5.

TABLE 17 First Component (A) = 3-tert-butylphenol Second Component (B) =terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli 10536 0.30 1.00 0.3 0.025 1.04 1 to 0.08 0.3 0.05 1.08 1 to 0.17 0.3 0.075 1.13 1to 0.25 0.4 0.1 1.50 1 to 0.25 0.08 0.3 0.77 1 to 3.75 0.1 0.3 0.83 1 to3 0 0.6 1.00

The ratios of 3-tert-butylphenol to terpineol tested ranged from 1/0.025to 1/400. The synergistic ratios of 3-tert-butylphenol to terpineolrange from 1/3 to 1/3.75.

TABLE 18 First Component (A) = 2-hydroxydiphenylmethane Second Component(B) = terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli10536 0.6 0 1.00 0.4 0.025 0.71 1 to 0.06 0.5 0.025 0.88 1 to 0.05 0.50.05 0.92 1 to 0.1 0.2 0.075 0.46 1 to 0.38 0.3 0.075 0.63 1 to 0.25 0.40.075 0.79 1 to 0.19 0.5 0.075 0.96 1 to 0.15 0.2 0.1 0.50 1 to 0.5 0.30.1 0.67 1 to 0.33 0.4 0.1 0.83 1 to 0.25 0.2 0.3 0.83 1 to 1.5 0 0.61.00

The ratios of 2-hydroxydiphenylmethane to terpineol tested ranged from1/0.025 to 1/400. The synergistic ratios of 2-hydroxydiphenylmethane toterpineol range from 1/0.05 to 1/1.5.

TABLE 19 First Component (A) = 4-hydroxydiphenylmethane Second Component(B) = terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli10536 0.5 0 1.00 0.3 0.025 0.64 1 to 0.08 0.4 0.025 0.84 1 to 0.06 0.40.05 0.88 1 to 0.13 0.3 0.075 0.73 1 to 0.25 0.4 0.075 0.93 1 to 0.190.2 0.1 0.57 1 to 0.5 0.3 0.1 0.77 1 to 0.33 0.4 0.1 0.97 1 to 0.25 0.20.3 0.90 1 to 1.5 0 0.6 1.00

The ratios of 4-hydroxydiphenylmethane to terpineol tested ranged from1/0.025 to 1/400. The synergistic ratios of 4-hydroxydiphenylmethane toterpineol range from 1/0.06 to 1/1.5.

TABLE 20 First Component (A) = 2-cyclopentylphenol Second Component (B)= terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli 105360.8 0 1.00 0.6 0.025 0.79 1 to 0.04 0.6 0.05 0.83 1 to 0.08 0.5 0.0750.75 1 to 0.15 0.6 0.075 0.88 1 to 0.13 0.5 0.1 0.79 1 to 0.2 0.6 0.10.92 1 to 0.17 0.3 0.3 0.88 1 to 1 0 0.6 1.00

The ratios of 2-cyclopentylphenol to terpineol tested ranged from1/0.025 to 1/400. The synergistic ratios of 2-cyclopentylphenol toterpineol range from 1/0.04 to 1/1.

TABLE 21 First Component (A) = 4-cyclopentylphenol Second Component (B)= terpineol Microorganism C_(a) C_(b) ΣFBC Ratio A to B E. coli 105360.6 0 1.00 0.4 0.025 0.71 1 to 0.06 0.5 0.025 0.88 1 to 0.05 0.6 0.051.08 1 to 0.08 0.3 0.075 0.63 1 to 0.25 0.4 0.075 0.79 1 to 0.19 0.4 0.10.83 1 to 0.25 0.1 0.3 0.67 1 to 3 0.2 0.3 0.83 1 to 1.5 0 0.6 1.00

The ratios of 4-cyclopentylphenol to terpineol tested ranged from1/0.025 to 1/400. The synergistic ratios of 4-cyclopentylphenol toterpineol range from 1/0.05 to 1/3.

The results of Examples 1 and 2 demonstrate that a synergisticantimicrobial effect of the monosubstituted phenols according to theinvention and terpineol are obtained over a wide range of concentrationsand ratios.

Example 3

The antimicrobial efficacy of compositions according to the invention,comprising a monosubstituted phenol (3-phenylphenol) and terpineol weretested following the same protocol and using the same terpineol asdescribed for Example 1. The results are presented in Table 22.

TABLE 22 Antibacterial activity of 3-phenylphenol alone and incombination with terpineol against E. coli Mono- substituted phenolConcentration N_(MBS) concentration of terpineol [log Standard ExampleC_((phenol))(% w/v) C_(TERP)(% w/v) CFU/ml] deviation 3:1* 0.125% 3- 04.3 0.4 phenylphenol 3:2* 0.05% 3- 0 7.4 0.1 phenylphenol 3:3* 0.025% 3-0 7.7 0.1 phenylphenol 3:4 X 0.125% 3- 0.15% alpha- 0.0 0.6 phenylphenolterpineol 3:5 Y 0.08% 3- 0.15% alpha- 0.0 0.0 phenylphenol terpineol 3:6Z 0.025% 3- 0.15% alpha- 0.0 0.0 phenylphenol terpineol *Examples markedwith an asterisk (*) are comparative examples

By analogous reasoning as described for Example 1, it follows fromcomparative examples (3:1) to (3:3) that the MBC of 3-phenylphenol underthe given conditions is at least 0.125% w/v. Similarly, ΣFBC values werecalculated. As shown by the data in Table 23, Examples (3:5) and (3:6)demonstrate that 3-phenylphenol and terpineol are capable ofsynergistically providing antimicrobial action.

TABLE 23 Extent of synergistic interactions between binary compoundmixtures for compositions providing complete bacterial kill Evi-monosubstituted phenol terpineol dence MBC % MBC % of Syn- compound Ex.(w/v) FBC^(a) (w/v) FBC^(b) ΣFBC ergy^(c) 3-phenylphenol 3:5 0.125 0.40.4 0.38 0.78 Yes 3-phenylphenol 3:6 0.125 0.2 0.4 0.38 0.58 Yes ^(a)FBCof phenol: C_(phenol)/MBC_(phenol) ^(b)FBC of terpineol:C_(terpineol)/MBC_(terpineol) ^(c)Criterion for synergy: (ΣFBC <1)

Example 4 Automated Assessment of Efficacy in Surfactant Base SamplePreparation

In these examples, the efficacy of combinations of monosubstitutedphenols and terpineol were tested in a surfactant cleansing formulationcomprising 2.85% sodium cocoyl glycinate and 1.85% sodiumlauroamphoacetate. This corresponds to a 50% in use dilution with waterof a typical neat formulation containing 5.7% cocoyl glycinate and 3.7%% sodium lauroamphoacetate during hand washing. Solutions were preparedsuch that the concentrations of the surfactant components and testactives were 1.1 times the final desired concentration in order to allowfor dilution with the bacterial inoculum in the test. The solutions weremanually adjusted to pH 10.0 by dropwise addition of sodium hydroxidesolution, as measured with a pH meter at ambient temperature. Solutionsof the monosubstituted phenols and/or terpineols were prepared at amaximum of 24 hours before testing. The same terpineol was used as inExample 1.

Test Methodology

The efficacy of the combinations of the present invention was determinedagainst the same bacterium as in Example 1, Escherichia coli (E.coli—ATCC #10536), at a concentration of approximately 1×10⁸ bacteriaper mL.

Tests were conducted using standard microtiter plate assays using anautomated liquid handling system. 270 μl of the surfactant test solutionwas pipetted into each well of the microtitre plate (Nunc F GammaIrradiated 96F untreated microtitre plates of clear polystyrene) and 30μl of the bacterial suspension was then added. After exactly 15 secondsof bacterial exposure, a 30 μl volume of bacterial cells was withdrawnand transferred to 270 μl of D/E quench solution. After 5 minutes in theD/E quench, the optical density (OD) was measured for each plate in turnat two specific wavelengths (450 nm and 590 nm). These provide a dualcheck of antimicrobial activity, as the OD₄₅₀ reading is specific forthe yellow colour of D/E quench when bacterial growth is observed,whereas OD₅₉₀ is specific for the initial purple colour of the D/Equench which is retained if no bacterial growth is observed. After thetime zero OD measurements, plates were then incubated at 37° C.overnight (16 hours) before repeating the OD measurements. Delta ODvalues were calculated by subtracting the OD values at 16 hours from theinitial value at time zero from those at time=16 hours. Bacterial growthis observed as an increase in OD₄₅₀ and a decrease in OD₅₉₀. To identifyantibacterially efficacious systems (those preventing appreciablebacterial growth after incubation), the following threshold changes inOD readings have been adopted: if (1). OD₄₅₀ increases by less than 0.2absorbance unit (AU) on incubation and (2). OD₅₉₀ decreases by less than0.35 AU on incubation. Conversely, where OD₄₅₀ increases by more than0.1 AU and OD₅₉₀ decreases by more than 0.1 AU after incubation,corresponding to a colour shift from purple to yellow, the test systemallows bacterial growth and is not deemed efficacious. Four replicatemeasurements in the same plate have been made for each test system. Thenumber of replicate wells showing either bacterial growth or no growthis also readily assessed by eye by following the colour change. Thymoland terpineol were tested both alone and in combination for comparisonpurposes.

Dose responses for individual components and binary mixtures of activesat a fixed concentration ratio were generated by sequential dilution ofliquors with further surfactant solution to obtain a series of endpointsranging from 0.2 to 0.025% of the monosubstituted phenol and 0.5% to0.0625% of the terpineol. In each case, binary mixtures were assessed inthe weight to weight ratio monosubstituted phenol to terpineol of 1:2.5.In some selected cases, the combinations were also tested at the weightratio 1:1.

TABLE 24 Antibacterial activities of thymol, or monosubstituted phenolsalone, and in combination with terpineol in model surfactant solutionDeltaOD DeltaOD C_(phenol) ^((a)) C_(terpineol) ^((b)) (450 nm) ^((c))(590 nm) ^((d)) Ex. (% w/v) (% w/v) Mean S.D.^((f)) Mean S.D^((f))N_(rep) ^((e)) 4:1* 0 0 −0.60 0.02 0.64 0.02 4 4:2* 0.2% thymol 0 −0.540.02 0.64 0.02 4 4:3* 0.175% thymol 0 −0.54 0.02 0.56 0.02 4 4:4* 0.15%thymol 0 −0.57 0.01 0.55 0.01 4 4:5* 0.125% thymol 0 −0.58 0.01 0.550.01 4 4:6* 0.1% thymol 0 −0.58 0.00 0.54 0.02 4 4:7* 0.075% thymol 0−0.59 0.01 0.54 0.01 4 4:8* 0.05% thymol 0 −0.58 0.03 0.55 0.01 4 4:9*0.025% thymol 0 −0.55 0.01 0.65 0.02 4 4:10* 0 0.5% −0.45 0.02 0.64 0.024 4:11* 0 0.4% −0.47 0.01 0.59 0.00 4 4:12* 0 0.35% −0.48 0.01 0.58 0.014 4:13* 0 0.3% −0.51 0.01 0.57 0.01 4 4:14* 0 0.25% −0.54 0.01 0.56 0.14 4:15* 0 0.2% −0.56 0.01 0.55 0.01 4 4:16* 0 0.15% −0.57 0.01 0.55 0.014 4:17* 0 0.1% −0.53 0.02 0.67 0.02 4 4:18* 0.2% 2-n-propylphenol 0 0.270.01 0.22 0.01 0 4:19* 0.175% 2-n-propylphenol 0 0.22 0.03 0.20 0.01 04:20* 0.15% 2-n-propylphenol 0 0.20 0.03 0.17 0.02 0 4:21* 0.125%2-n-propylphenol 0 0.18 0.03 0.16 0.01 0 4:22* 0.1% 2-n-propylphenol 0−0.49 0.02 0.58 0.01 4 4:23* 0.075% 2-n-propylphenol 0 −0.46 0.02 0.570.01 4 4:24 0.2% 2-n-propylphenol 0.5% 0.26 0.01 0.26 0.00 0 4:25 0.175%2-n-propylphenol 0.4375% 0.27 0.01 0.25 0.02 0 4:26 0.15%2-n-propylphenol 0.375% 0.26 0.01 0.25 0.03 0 4:27 0.125%2-n-propylphenol 0.3125% 0.26 0.02 0.25 0.02 0 4:28 0.1%2-n-propylphenol 0.25% 0.26 0.02 0.24 0.02 0 4:29* 0.075%2-n-propylphenol 0.1875% −0.37 0.02 0.64 0.01 4 4:30* 0.2%3-n-propylphenol 0 −0.09 0.02 0.10 0.01 0 4:31* 0.175% 3-n-propylphenol0 −0.10 0.03 0.11 0.02 0 4:32* 0.15% 3-n-propylphenol 0 −1.11 0.03 0.600.02 4 4:33* 0.125% 3-n-propylphenol 0 −1.36 0.06 0.45 0.03 4 4:34* 0.1%3-n-propylphenol 0 −1.33 0.10 0.50 0.10 4 4:35 0.2% 3-n-propylphenol0.2% −0.09 0.01 0.12 0.05 0 4:36 0.175% 3-n-propylphenol 0.175% −0.090.01 0.10 0.01 0 4:37 0.15% 3-n-propylphenol 0.15% −0.05 0.09 0.16 0.080 4:38 0.125% 3-n-propylphenol 0.125% −0.88 0.12 0.62 0.05 4 4:39 0.2%3-n-propylphenol 0.5% −0.11 0.00 0.10 0.01 0 4:40 0.175%3-n-propylphenol 0.4375% −0.04 0.06 0.14 0.06 0 4:41 0.15%3-n-propylphenol 0.375% −0.07 0.06 0.10 0.01 0 4:42 0.125%3-n-propylphenol 0.3125% −0.09 0.02 0.13 0.02 0 4:43 0.1%3-n-propylphenol 0.25% −0.46 0.42 0.41 0.33 2 4:44 0.075%3-n-propylphenol 0.1875% −1.25 0.03 0.54 0.01 4 4:45* 0.2%4-n-propylphenol 0 −0.51 0.02 0.66 0.02 4 4:46* 0.175% 4-n-propylphenol0 −0.54 0.02 0.57 0.02 4 4:47* 0.15% 4-n-propylphenol 0 −0.56 0.02 0.540.02 4 4:48* 0.125% 4-n-propylphenol 0 −0.56 0.01 0.55 0.02 4 4:49 0.2%4-n-propylphenol 0.5% 0.21 0.03 0.28 0.02 0 4:50 0.175% 4-n-propylphenol0.4375% 0.18 0.02 0.22 0.02 0 4:51 0.15% 4-n-propylphenol 0.375% 0.070.11 0.17 0.05 0 4:52* 0.125% 4-n-propylphenol 0.3125% −0.30 0.39 0.670.25 4 4:53* 0.2% 4-n-butylphenol 0 −0.51 0.01 0.64 0.02 4 4:54* 0.175%4-n-butylphenol 0 −0.55 0.03 0.54 0.03 4 4:55* 0.15% 4-n-butylphenol 0−0.55 0.01 0.54 0.02 4 4:56* 0.125% 4-n-butylphenol 0 −0.58 0.01 0.530.02 4 4:57 0.2% 4-n-butylphenol 0.5% 0.17 0.01 0.25 0.03 0 4:58 0.175%4-n-butylphenol 0.4375% 0.19 0.05 0.20 0.02 0 4:59 0.15% 4-n-butylphenol0.375% −0.02 0.29 0.25 0.17 1 4:60* 0.125% 4-n-butylphenol 0.3125% −0.490.01 0.55 0.03 4 4:61* 0.2% 2-tert-butylphenol 0 −0.11 0.01 0.09 0.01 04:62* 0.175% 2-tert-butylphenol 0 −0.11 0.12 0.14 0.06 0 4:63* 0.15%2-tert-butylphenol 0 −0.39 0.33 0.36 0.29 2 4:64* 0.125%2-tert-butylphenol 0 −1.23 0.17 0.54 0.09 4 4:65* 0.1%2-tert-butylphenol 0 −1.45 0.09 0.38 0.04 4 4:66* 0.075%2-tert-butylphenol 0 −1.48 0.13 0.40 0.13 4 4:67* 0.05%2-tert-butylphenol 0 −1.46 0.13 0.40 0.12 4 4:68 0.2% 2-tert-butylphenol0.2% −0.09 0.02 0.10 0.02 0 4:69 0.175% 2-tert-butylphenol 0.175% −0.100.02 0.10 0.03 0 4:70 0.15% 2-tert-butylphenol 0.15% −0.10 0.01 0.100.01 0 4:71 0.125% 2-tert-butylphenol 0.125% −0.09 0.05 0.13 0.06 0 4:720.1% 2-tert-butylphenol 0.1% −0.88 0.59 0.54 0.16 3 4:73* 0.075%2-tert-butylphenol 0.075% −1.41 0.11 0.46 0.11 4 4:74 0.2%2-tert-butylphenol 0.5% −0.12 0.01 0.10 0.01 0 4:75 0.175%2-tert-butylphenol 0.4375% −0.11 0.01 0.10 0.01 0 4:76 0.15%2-tert-butylphenol 0.375% −0.11 0.02 0.13 0.05 0 4:77 0.125%2-tert-butylphenol 0.3125% −0.11 0.03 0.13 0.01 0 4:78 0.1%2-tert-butylphenol 0.25% −0.09 0.06 0.12 0.01 0 4:79 0.075%2-tert-butylphenol 0.1875% −0.43 0.65 0.24 0.12 1 4:80* 0.05%2-tert-butylphenol 0.125% −1.41 0.09 0.47 0.10 4 4:81* 0.2%3-tert-butylphenol 0 −1.39 0.05 0.44 0.05 4 4:82* 0.175%3-tert-butylphenol 0 −1.41 0.03 0.43 0.02 4 4:83* 0.15%3-tert-butylphenol 0 −1.46 0.05 0.41 0.04 4 4:84* 0.125%3-tert-butylphenol 0 −1.45 0.06 0.39 0.04 4 4:85* 0.1%3-tert-butylphenol 0 −1.48 0.08 0.37 0.04 4 4:86* 0.075%3-tert-butylphenol 0 −1.50 0.03 0.34 0.03 4 4:87 0.2% 3-tert-butylphenol0.2% −0.11 0.00 0.09 0.01 0 4:88 0.175% 3-tert-butylphenol 0.175% −0.110.00 0.10 0.01 0 4:89 0.15% 3-tert-butylphenol 0.15% −0.72 0.51 0.470.23 3 4:90* 0.125% 3-tert-butylphenol 0.125% −1.34 0.06 0.50 0.06 44:91 0.2% 3-tert-butylphenol 0.5% −0.12 0.01 0.10 0.01 0 4:92 0.175%3-tert-butylphenol 0.4375% −0.10 0.03 0.11 0.01 0 4:93 0.15%3-tert-butylphenol 0.375% −0.09 0.03 0.13 0.02 0 4:94 0.125%3-tert-butylphenol 0.3125% −0.14 0.04 0.16 0.12 0 4:95 0.1%3-tert-butylphenol 0.25% −0.62 0.49 0.45 0.25 2 4:96* 0.075%3-tert-butylphenol 0.1875% −1.34 0.08 0.47 0.05 4 4:97* 0.2%4-tert-butylphenol 0 −0.74 0.05 0.47 0.06 4 4:98* 0.175%4-tert-butylphenol 0 −0.71 0.08 0.41 0.06 4 4:99 0.2% 4-tert-butylphenol0.5% 0.19 0.04 0.26 0.04 0 4:100* 0.175% 4-tert-butylphenol 0.4375%−0.42 0.04 0.74 0.06 4 4:101* 0.2% 2-sec-butylphenol 0 −0.46 0.01 0.640.02 4 4:102* 0.175% 2-sec-butylphenol 0 −0.52 0.01 0.54 0.02 4 4:103*0.15% 2-sec-butylphenol 0 −0.55 0.02 0.53 0.02 4 4:104* 0.125%2-sec-butylphenol 0 −0.55 0.01 0.55 0.01 4 4:105 0.2% 2-sec-butylphenol0.5% 0.24 0.02 0.24 0.03 0 4:106 0.175% 2-sec-butylphenol 0.4375% 0.190.04 0.19 0.01 0 4:107 0.15% 2-sec-butylphenol 0.375% 0.15 0.02 0.160.01 0 4:108* 0.125% 2-sec-butylphenol 0.3125% −0.46 0.01 0.54 0.03 44:109* 0.2% 4-sec-butylphenol 0 −0.50 0.02 0.64 0.02 4 4:110* 0.175%4-sec-butylphenol 0 −0.55 0.02 0.52 0.02 4 4:111* 0.15%4-sec-butylphenol 0 −0.55 0.02 0.54 0.02 4 4:112* 0.125%4-sec-butylphenol 0 −0.42 0.32 0.52 0.02 4 4:113 0.2% 4-sec-butylphenol0.5% 0.19 0.02 0.26 0.02 0 4:114 0.175% 4-sec-butylphenol 0.4375% 0.180.04 0.19 0.02 0 4:115 0.15% 4-sec-butylphenol 0.375% −0.15 0.37 0.420.18 3 4:116 0.125% 4-sec-butylphenol 0.3125% −0.48 0.02 0.56 0.02 44:117* 0.2% 4-pentylphenol 0 −0.51 0.01 0.61 0.02 4 4:118 0.2%4-pentylphenol 0.5% −0.41 0.02 0.63 0.03 4 4:119* 0.2% 4-hexylphenol 0−0.50 0.02 0.62 0.03 4 4:120* 0.2% 4-hexylphenol 0.5% −0.43 0.02 0.640.02 4 4:121* 0.2% 3-phenylphenol 0 −0.65 0.05 0.48 0.05 4 4:122* 0.175%3-phenylphenol 0 −0.68 0.08 0.43 0.03 4 4:123* 0.15% 3-phenylphenol 0−0.61 0.03 0.48 0.03 4 4:124* 0.125% 3-phenylphenol 0 −0.62 0.02 0.490.02 4 4:125* 0.1% 3-phenylphenol 0 −0.61 0.02 0.51 0.01 4 4:126 0.2%3-phenylphenol 0.5% 0.27 0.02 0.24 0.02 0 4:127 0.175% 3-phenylphenol0.4375% 0.23 0.06 0.22 0.04 0 4:128 0.15% 3-phenylphenol 0.375% 0.160.10 0.22 0.05 0 4:129 0.125% 3-phenylphenol 0.3125% −0.15 0.38 0.490.18 2 4:130 0.1% 3-phenylphenol 0.25% −0.46 0.08 0.64 0.05 4 4:131*0.2% 2-benzylphenol 0 −0.44 0.03 0.67 0.63 4 4:132* 0.175%2-benzylphenol 0 −0.44 0.01 0.62 0.60 4 4:133* 0.15% 2-benzylphenol 0−0.47 0.03 0.58 0.57 4 4:134* 0.125% 2-benzylphenol 0 −0.50 0.02 0.560.55 4 4:135* 0.1% 2-benzylphenol 0 −0.52 0.03 0.56 0.54 4 4:136* 0.075%2-benzylphenol 0 −0.52 0.03 0.57 0.55 4 4:137* 0.05% 2-benzylphenol 0−0.54 0.03 0.61 0.60 4 4:138 0.2% 2-benzylphenol 0.5% 0.09 0.03 0.100.04 0 4:139 0.175% 2-benzylphenol 0.4375% 0.14 0.03 0.16 0.01 0 4:1400.15% 2-benzylphenol 0.375% 0.10 0.09 0.15 0.03 0 4:141 0.125%2-benzylphenol 0.3125% 0.09 0.02 0.10 0.01 0 4:142 0.1% 2-benzylphenol0.25% −0.03 0.34 0.29 0.21 2 4:143 0.075% 2-benzylphenol 0.1875% −0.260.39 0.43 0.19 3 4:144 0.05% 2-benzylphenol 0.125% −0.50 0.04 0.56 0.004 4:145* 0.2% 4-benzylphenol 0 −0.55 0.02 0.62 0.03 4 4:146* 0.175%4-benzylphenol 0 −0.53 0.02 0.63 0.03 4 4:147* 0.15% 4-benzylphenol 0−0.53 0.01 0.64 0.02 4 4:148* 0.125% 4-benzylphenol 0 −0.55 0.02 0.640.03 4 4:149 0.2% 4-benzylphenol 0.5% 0.21 0.03 0.28 0.04 0 4:150 0.175%4-benzylphenol 0.4375% 0.18 0.03 0.22 0.01 0 4:151 0.15% 4-benzylphenol0.375% −0.14 0.36 0.38 0.22 2 4:152 0.125% 4-benzylphenol 0.3125% −0.480.02 0.64 0.03 4 4:153* 0.2% 2-cyclopentyl-phenol 0 −1.55 0.04 0.36 0.334 4:154* 0.175% 2-cyclopentyl- 0 −1.58 0.07 0.39 0.33 4 phenol 4:155*0.15% 2-cyclopentyl-phenol 0 −1.61 0.07 0.34 0.30 4 4:156* 0.125%2-cyclopentyl- 0 −1.58 0.08 0.36 0.31 4 phenol 4:157* 0.1%2-cyclopentyl-phenol 0 −1.57 0.10 0.40 0.30 4 4:158 0.2%2-cyclopentyl-phenol 0.5% −0.12 0.01 0.10 0.01 0 4:159* 0.175%2-cyclopentyl- 0.4375% −0.11 0.01 0.10 0.01 0 phenol 4:160 0.15%2-cyclopentyl-phenol 0.375% −0.12 0.01 0.12 0.02 0 4:161 0.125%2-cyclopentyl- 0.3125% −0.41 0.35 0.40 0.33 2 phenol 4:162 0.1%2-cyclopentyl-phenol 0.25% −1.28 0.11 0.53 0.06 4 4:163* 0.2%4-cyclopentyl-phenol 0 −0.48 0.01 0.66 0.03 4 4:164* 0.175%4-cyclopentyl- 0 −0.48 0.02 0.57 0.02 4 phenol 4:165 0.2%4-cyclopentyl-phenol 0.5% 0.04 0.28 0.36 0.15 1 4:166 0.175%4-cyclopentyl- 0.4375% −0.41 0.01 0.63 0.02 4 phenol 4:167* 0.2%(E)-2-(prop-1-enyl)- 0 −1.29 0.05 0.52 0.03 4 phenol 4:168* 0.175%(E)-2-(prop-1-enyl)- 0 −1.41 0.03 0.43 0.02 4 phenol 4:169* 0.15%(E)-2-(prop-1-enyl)- 0 −1.43 0.04 0.40 0.03 4 phenol 4:170* 0.125%(E)-2-(prop-1-enyl)- 0 −1.45 0.02 0.39 0.02 4 phenol 4:171* 0.1%(E)-2-(prop-1-enyl)- 0 −1.45 0.02 0.39 0.01 4 phenol 4:172* 0.075%(E)-2-(prop-1-enyl)- 0 −1.44 0.03 0.39 0.01 4 phenol 4:173 0.2%(E)-2-(prop-1-enyl)- 0.2% −0.11 0.10 0.10 0.01 0 phenol 4:174 0.175%(E)-2-(prop-1-enyl)- 0.175% −0.08 0.05 0.12 0.05 0 phenol 4:175 0.15%(E)-2-(prop-1-enyl)- 0.15% −0.80 0.50 0.56 0.30 3 phenol 4:176 0.125%(E)-2-(prop-1-enyl)- 0.125% −1.27 0.08 0.57 0.05 4 phenol 4:177 0.2%(E)-2-(prop-1-enyl)- 0.5% −0.11 0.01 0.10 0.01 0 phenol 4:178 0.175%(E)-2-(prop-1-enyl)- 0.4375% −0.11 0.02 0.11 0.01 0 phenol 4:179 0.15%(E)-2-(prop-1-enyl)- 0.375% −0.11 0.01 0.12 0.01 0 phenol 4:180 0.125%(E)-2-(prop-1-enyl)- 0.3125% −0.12 0.01 0.12 0.01 0 phenol 4:181 0.1%(E)-2-(prop-1-enyl)- 0.25% −0.35 0.49 0.28 0.28 1 phenol 4:182 0.075%(E)-2-(prop-1-enyl)- 0.1875% −1.27 0.05 0.58 0.04 4 phenol *Examplesmarked with an asterisk (*) are comparative examples ^((a))Concentration of thymol or monosubstituted phenol as specified^((b))Concentration of terpineol ^((c)) DeltaOD (450 nm) = OD₄₅₀ (time =16 hours) − OD₄₅₀ (time zero) ^((d)) DeltaOD (590 nm) = OD₅₉₀ (time = 16hours) − OD₅₉₀ (time zero) ^((e)) N_(rep) = No. of replicates showinggrowth (out of 4) ^((f))S.D. = standard deviation

TABLE 25 Minimum biocidal concentrations of antimicrobial components in2.85% sodium cocoyl glycinate + 1.85% sodium, lauroamphoacetate solutionat pH 10 Component MBC (% w/v) Thymol >0.2 alpha-terpineol >0.52-n-propylphenol 0.125 3-n-propylphenol 0.175 4-n-propylphenol >0.24-n-butylphenol >0.2 2-tert-butylphenol 0.175 3-tert-butylphenol >0.24-tert-butylphenol >0.2 2-sec-butylphenol >0.2 4-sec-butylphenol >0.24-pentylphenol >0.2 3-phenylphenol >0.2 2-benzylphenol >0.24-benzylphenol >0.2 2-cyclopentylphenol >0.2 4-cyclopentylphenol >0.2(E)-2-(prop-1-enyl)phenol >0.2

Results

The surfactants used are not themselves antimicrobially active againstE. coli at the concentrations employed as shown by the results of Ex.(4:1) in Table 24. Thus, any antimicrobial efficacy can be ascribed tothe monosubstituted phenols and/or terpineol. Table 25 presentsMBC-values determined similarly as described for Example 1. Many of thetested monosubstituted phenols have an MBC higher than the highesttested concentrations, in the presence of the specified surfactants.

The results of Table 24 show that with the exceptions of4-cyclopentylphenol, 4-pentylphenol and 4-hexylphenol, all themonosubstituted phenols tested show 15 second bactericidal efficacy(complete kill in all 4 replicates) against E. coli when tested incombination with alpha-terpineol at concentrations lower than their MBCin the same surfactant formulation (comprising cocoyl glycinate andlauroamphoacetate). This is true for both for the 1:1 and 1:2.5mono-substituted phenol: alpha terpineol ratios but efficacy ismaintained at lower monosubstituted phenol concentrations when thehigher ratio of alpha-terpineol is present. 4-Hexylphenol is acomparative monosubstituted phenol.

Thus, it was found that monosubstituted phenols according to theinvention and in particular 2-n-propylphenol. 3-n-propylphenol,4-n-propylphenol, 4-n-butylphenol, 2-tert-butylphenol,3-tert-butylphenol, 4-tert-butylphenol, 2-sec-butylphenol,4-sec-butylphenol, 3-phenylphenol, 2-benzylphenol, 4-benzylphenol,2-cyclopentylphenol, (E)-2-(prop-1-enyl)phenol show enhancedantimicrobial action in combination with terpineol in the presence ofsurfactant, in particular cocoyl glycinate and lauroamphoacetate.

1. An antimicrobial composition comprising: i. 0.001 to 5% by weight ofone or more monosubstituted phenols, ii. 0.001 to 5% by weight ofterpineol, and iii. a carrier: wherein the one or more monosubstitutedphenols have the following structure

wherein the substituent R₁ is selected from the group consisting oflinear C₃ to C₅ alkyl, isopropyl, branched C₄ alkyl, linear C₃ to C₅alkenyl, linear C₄ or C₅ alkadienyl, branched C₄ alkenyl, cyclopentyl,cyclopentenyl, cyclohexyl, cyclohexenyl, phenyl, and benzyl; and whereinthe terpineol is selected from the group consisting of alpha-terpineol,beta-terpineol, gamma-terpineol, delta-terpineol, 4-terpineol, andmixtures thereof.
 2. An antimicrobial composition according to claim 1,wherein the substituent R₁ is selected from the group consisting oflinear C₃ to C₅ alkyl, branched C₄ alkyl, linear C₃ to C₅ alkenyl,linear C₄ or C₅ alkadienyl, branched C₄ alkenyl, cyclopentyl,cyclopentenyl, cyclohexyl, cyclohexenyl, phenyl, and benzyl.
 3. Anantimicrobial composition according to claim 2, wherein the substituentR₁ is a branched C₄ alkyl or a branched C₄ alkenyl group.
 4. Anantimicrobial composition according to claim 3, wherein the substituentR₁ is selected from the group consisting of tert-butyl, sec-butyl, andisobutyl.
 5. An antimicrobial composition according to claim 2 whereinthe one or more monosubstituted phenols are selected from the groupconsisting of 4-propylphenol, 4-n-butylphenol, 4-pentylphenol,2-tert-butylphenol, 3-tert-butylphenol, 2-sec-butylphenol,4-sec-butylphenol, 2-cyclopentylphenol, 4-cyclopentylphenol,2-cyclohexylphenol 2-(prop-1-enyl)phenol, 2-allylphenol, 3-phenylphenol,2-benzylphenol, and 4-benzylphenol.
 6. An antimicrobial compositionaccording to claim 4 wherein the one or more monosubstituted phenols areselected from the group consisting of 2-tert-butylphenol,3-tert-butylphenol, 2-sec-butylphenol, and 4-sec-butylphenol.
 7. Anantimicrobial composition according to any one of claims 1 to 6comprising i. 0.01 to 0.4% by weight of the one or more monosubstitutedphenols, and ii. 0.05 to 1% by weight of the terpineol.
 8. Anantimicrobial composition according to any one of claims 1 to 7comprising from 1 to 80% by weight of one or more surfactants.
 9. Anantimicrobial composition according to claim 8 wherein the one or moresurfactants are anionic, nonionic, or a combination of anionic andnonionic surfactants.
 10. An antimicrobial composition according toclaim 7 or 8 wherein the one or more surfactants are selected from thegroup consisting of soaps, alkyl sulphates and linear alkyl benzenesulphonates.
 11. A solid antimicrobial composition according to any oneof claims 8 to 10 comprising: a. 0.05 to 5% by weight of the one or moremonosubstituted phenols, b. 0.05 to 5% by weight of the terpineol, c. 5to 30% by of weight water, and; d. 30 to 80% by weight of the one ormore surfactants.
 12. A method of disinfecting a surface comprising thesteps of a. applying a composition according to any one of the precedingclaims on to the surface; and b. removing the composition from thesurface.
 13. A method according to claim 12, wherein the disinfectiontime T of said method is less than 300 seconds, preferably less than 60seconds, and more preferably less than 15 seconds; wherein T is definedas the time that elapses from the moment of adding the composition to amicrobial culture until the number of microbes per unit volume of theculture is reduced by a factor of 100 000; and wherein the initialnumber of microbes preferably exceeds about 100 000 000 microbes permillilitre and wherein the composition is preferably a liquidcomposition.
 14. Use of a composition according to any one of claims 1to 11 for improved hand hygiene.
 15. Use of a composition according toany one of claims 1 to 11 for improved oral hygiene.